Reviewing the past five hundred years, the Harvard Thucydides’s Trap Project has identified sixteen cases in which a major rising power has threatened to displace a major ruling power. Twelve of these sixteen rivalries ended in war.

The Thucydides’s Trap Case File (below) presents summaries of all sixteen cases, which are featured in Graham Allison's new book Destined for War: Can America and China Escape Thucydides's Trap? Using the cases, Allison illustrates how tension between rising and ruling powers has often led to war—while also showing how war was avoided in the four rivalries that did not end in violence.

“It was the rise of Athens and the fear that this instilled in Sparta that made war inevitable.”

Thucydides, History of the Peloponnesian War

Below, you can read our summaries of the sixteen cases in which a major ruling power has been challenged by a major rising power over the past 500 years. We also invite readers to:

  • Review the list of potential additional cases under review for inclusion in Phase II of the Project, as well as the methodology used to compile the Case File.
  • Contribute to the Project by identifying additional cases for consideration in Phase II, providing feedback on the current Case File, or offering other comments and suggestions.

We have received hundreds of comments since launching this website in 2015—selections are posted here. Critical feedback is valuable for the Thucydides's Trap Project, and we will continue to post responses that advance the conversation. To engage critiques and clarify misconceptions, we have responded to seven common issues and questions raised about this effort.

Thucydides's Trap Case File

*You can download a graphic version of the case file here

Period   —   Ruling Power vs. Rising Power   —   Outcome

  • 1. Late 15th century — Portugal vs. Spain — NO WAR

    Period: Late 15th century
    Ruling power: Portugal
    Rising power: Spain
    Domain: Global empire and trade
    Outcome: No war

    For most of the fifteenth century, Portugal overshadowed its traditional rival and neighbor, the Spanish Crown of Castile, by leading the world in exploration and international trade. By the 1490s, however, a united, rejuvenated Spain began to challenge Portugal’s trade dominance and claim colonial supremacy in the New World, bringing the two Iberian powers to the brink of war. An intervention by the pope and the 1494 Treaty of Tordesillas narrowly staved off a devastating conflict.

    In the mid-fifteenth century, the ambitious prince Henry the Navigator emerged as the chief proponent of Portuguese exploration. He invested in new seafaring technologies and dispatched the Portuguese navy on far-flung expeditions to seek gold, foster new trading partnerships, and spread Christianity. With Portugal’s chief rival, Castile, preoccupied with a war over its monarchical succession and its reconquest of the remaining Islamic strongholds on the Iberian Peninsula, Portuguese trading preeminence was secure. Henry therefore had “free hands to undertake a dynamic and coherent policy of expansion”1 in Madeira, the Azores, and the coastal territories of West Africa. Portuguese mastery of the seas reached its apex in 1488, when the explorer Bartolomeu Dias became the first European to round the Cape of Good Hope, pointing to a future sea route to India and the lucrative East Indies.

    But even as Lisbon’s empire continued to grow, its Castilian rival was positioning itself to challenge Portuguese supremacy. The dynastic marriage between Catholic monarchs Isabella of Castile and Ferdinand of Aragon in 1469 united those two kingdoms under a single crown and quickly centralized power in the Spanish-speaking world.2 In 1492, Ferdinand and Isabella completed their reconquest of the final emirate on the Iberian Peninsula, Granada.

    Though Portugal maintained an edge when it came to overseas expansion— Spain’s empire extended no farther than the Canary Islands—it did not take long for Spain’s rise to worry ruling Portugal. After the 1492 recapture of Granada, Lisbon worried that “the victorious Castilians might now be expected to carry their war into North Africa, posing a threat to Portugal’s ambitions in that quarter.”3 Portugal’s concerns grew after Christopher Columbus reached the New World in 1492. Spurned by King John II when he at first appealed to Portugal for support, Columbus turned to Ferdinand and Isabella, who backed him in return for nine-tenths of the revenues from the lands he laid claim to.4 Columbus’s voyages turned Spain into a serious rival for overseas empire.

    The balance of power between the two rivals changed almost overnight. According to economic historian Alexander Zukas, “It was clear that conflict would soon arise over the rival claims of Spain and Portugal to lands previously unclaimed by Europeans.”5 Indeed, when rumor arose in Spain that King John, “convinced that the islands which Columbus had discovered belonged to him…was already preparing a fleet to take possession of them,” war between the two powers seemed likely.6

    Remembering the bitter lessons of the War of Castilian Succession in the 1470s, in which Castile, Aragon, and Portugal fought for five years to an essential stalemate, Spain turned to the Spanish-descended Pope Alexander VI for arbitration, in whom it found a sympathetic ear. Alexander demarcated a line — about 320 miles west of the Cape Verde Islands—and determined that any new lands discovered east of the line should belong to Portugal, and any west of the line to Spain.7 The Portuguese, however, were furious with the ruling and refused to abide by it because of its meager share of the New World and the restriction placed on its access to trade routes in India and Africa.8

    In a last-ditch attempt to avoid war, the two powers agreed to modify the pope’s proposal in the 1494 Treaty of Tordesillas. The treaty moved the dividing line westward to the 46th meridian, cutting through modern-day eastern Brazil, and granted Portugal trade access to India and Africa. As historian A. R. Disney has argued, Tordesillas “became a basic charter of empire, defining their respective spheres of ‘conquest’ and influence well into the eighteenth century.”9 The agreement held despite further exploration of the vast American continent, which revealed that Spain had gotten the far better end of the deal in the Americas.10

    Why did the two powers not fight, even after Portugal realized that Spain’s discoveries would significantly sway the balance of power? One reason was that King John II knew Portugal “could ill-afford another war with Spain,”11 and Spain too, having just completed its reconquest of Granada, was constrained economically and militarily. The memory of the War of Castilian Succession surely dampened hopes of a decisive victory. But more important, Pope Alexander’s bulls carried behind them the threat of papal excommunication, a devastating blow to the prestige of any Catholic monarch. The pope could stave off war because both the Spanish and Portuguese crowns saw their own legitimacy as more important than the balance of power.

    The Treaty of Tordesillas survived the test of time.12 Though Spain and Portugal continued to compete, they recognized a shared interest in excluding other powers from the New World. As Britain, France, and the Netherlands surpassed them in economic and military might, Spain and Portugal increasingly clung to their Vatican-approved positions as guardians of the status quo.13

  • 2. First half of 16th century — France vs. Hapsburgs — WAR

    Period: First half of 16th century
    Ruling power: France
    Rising power: Hapsburgs
    Domain: Land power in western Europe
    Outcome: Hapsburg-Valois Wars (1519–59), including Italian War (1521–26)

    King Charles of Spain’s 1519 election as Holy Roman emperor emboldened the rising House of Hapsburg and challenged French preeminence in Europe. Determined to maintain French influence over Western Europe and fearful of Hapsburg encirclement, France’s King Francis I rallied his allies to invade Hapsburg-controlled lands, beginning forty years of intermittent war between the rival land powers that ended with a century of Hapsburg supremacy.

    After dismantling and annexing half of the powerful Duchy of Burgundy in 1477 and the Duchy of Brittany in 1491, France began the sixteenth century as Western Europe’s predominant land power. Its growing prosperity led Pope Leo X in 1519 to declare that King Francis I of France “surpassed in wealth and power all other Christian kings.”14 That year, Francis was a leading contender to succeed Maximilian I as Holy Roman emperor, but electoral corruption gave the title instead to the Hapsburg successor, King Charles of Spain. Immediately after Charles’s election — a massive boon for the rising Hapsburgs — Francis “forecast war — not against the Infidel, but between himself and Charles.”15

    For Francis, there was much to fear in Charles’s appointment. A list of interrelated feuds between the two rulers — over Navarre (a Hapsburg possession, which Francis claimed), Burgundy (a French possession, which Charles claimed), and control of the Duchy of Milan — meant that Charles’s new advantage posed a serious threat to French power. It also raised the prospect of encirclement by Hapsburg lands.16

    The Spanish king’s influence — and his neighbors’ anxiety — grew as he consolidated his rule over Hapsburg-controlled parts of the Holy Roman Empire, the Netherlands, territories in Franche-Comté and modern-day Italy, and Spain’s empire in the New World. “Whether Charles V aspired to a universal empire or not,” historian John Lynch observes, “the fact remained that even without counting any of the territories in dispute — Milan and Burgundy — his dominions were already too universal and injured too many interests not to provoke widespread resentment.”17 Francis, according to historian Robert Knecht, had voiced these concerns prior to Charles’s coronation as emperor, and sought the position himself mainly because “if [Charles] were to succeed, seeing the extent of his kingdoms and lordships, this could do me immeasurable harm.”18

    In an effort to reverse Charles’s rise, Francis pushed allies to invade Hapsburg-controlled lands in Navarre (part of modern-day northeast Spain and southwest France) and Luxembourg. Charles reacted by enlisting English and papal support against France’s aggression, successfully invading French lands in Italy. Francis was captured in the 1525 Battle of Pavia and imprisoned in Madrid. To win release, he had to renounce his claims in Italy, Burgundy, Flanders, and Artois in the Treaty of Madrid of 1526. Charles’s growing power and his degrading treatment of the French monarch sent tremors across Europe, making it much easier for Francis to forge a countervailing coalition when he returned to Paris. His alliance included such unlikely partners as the new pope, Clement VII, and Sultan Suleiman of the Ottoman Empire (see case 3). It was insufficient, however, to prevent Charles from invading much of Italy in early 1527, culminating in the shocking sack of Rome and the capture of Pope Clement himself in May.

    The struggle between France and the Hapsburgs continued intermittently until the late 1550s, even as the Ottoman Empire rose to threaten Hapsburg power. At that point, having exhausted their finances, both sides agreed to shelve their hostilities. A long peace paved the way for the new Spanish Hapsburg king, Philip II, to enjoy “undisputed supremacy in Christendom,”19 while France dealt with decades of domestic turmoil in the French Wars of Religion. Conflict resumed during the early 1600s, as King Philip IV of Spain faced a rising France under King Louis XIII. Under his successor, the Sun King, Louis XIV, France became continental Europe’s preeminent power once more.

  • 3. 16th and 17th centuries — Hapsburgs vs. Ottoman Empire — WAR

    Period: 16th and 17th centuries
    Ruling power: Hapsburgs
    Rising power: Ottoman Empire
    Domain: Land power in central and eastern Europe, sea power in the Mediterranean
    Outcome: Ottoman-Hapsburg wars, including wars of Suleiman the Magnificent (1526–66), Long War (1593–1606), and Great Turkish War (1683–99)

    The rapid expansion of Ottoman territory and resources in the early 1500s threatened to upend the status quo of a Hapsburg-dominated Europe, particularly as Turkish ambitions to expand into Eastern Europe and the Balkans became a reality. This expansion pitted the two powers against each other in a series of wars that included the Ottoman seizure of much of Eastern Europe and confirmed the empire’s rise to continental preeminence.

    With the powerful Hapsburg Charles V’s election as Holy Roman emperor in 1519, a “universal monarchy, in which the Hapsburgs ruled over a united and once again uniformly Catholic Christendom, seemed a realistic possibility.”20 When Charles defeated France in the Italian War five years later (see case 2), he achieved a dominant position in Europe, controlling Austria, Spain, southern Italy, and the present-day Netherlands. In 1525, in an act of desperation, the vanquished Francis I sought an alliance with the erstwhile enemy of all the European great powers: the Ottoman Empire under Sultan Suleiman the Magnificent. In the words of historian Halil İnalcık, the Ottomans represented to Francis “the only power capable of guaranteeing the existence of the European states against Charles V.”21

    Ottoman ambition was undeniable. Midway through the previous century, Sultan Mehmed the Conqueror had sacked the Byzantine capital of Constantinople, instilling throughout Christian Europe the fear of “an ever more aggressive policy of conquest.”22 At the turn of the sixteenth century, the Second Ottoman-Venetian War transformed the Ottoman Empire into a formidable naval power, with over four hundred ships by 1515 and over one hundred docks on the Black Sea by the early 1520s.23 Eight years before Francis’s plea, the Ottomans completed their conquest of the Mamluk Empire, annexing modern-day Egypt, Syria, and the Arabian Peninsula, and doubling the sultan’s territory and tax base. According to Andrew Hess, these conquests “immeasurably strengthened the Ottoman state,” providing economic benefits and religious legitimacy in the Islamic world.24 Using their newfound naval power and wealth, the Ottomans expanded their sphere of influence west into the Mediterranean Sea and northwest toward Vienna.25 Beyond the walls of Vienna lay Charles’s Holy Roman Empire.

    In 1526, Suleiman attacked Hungary in the Battle of Mohács, seizing a third of its territory. King Louis II of Hungary died during the retreat. As Suleiman marched on toward the Austrian border, Charles became, as Richard Mackenney puts it, “preoccupied” by the seemingly “invincible and all-conquering” invaders. In 1527, he convoked the Castilian Cortes (Spanish legislature) “to organize the necessary means of defense against the Turks,”26 whose ultimate goal, Charles knew, was the Holy Roman Empire itself. “It was there that their main enemy, the Hapsburgs, and the German princes who supported them, could be dealt a decisive blow,” writes historian Brendan Simms. “Moreover, it was only by occupying Germany that Suleiman could vindicate the Ottoman claim to the legacy of the Roman Empire.”27

    The spark that ignited war between the two powers came quickly. Fearing that the Ottomans would exploit the power vacuum in Hungary following Louis II’s death, the Hapsburg archduke of Austria Ferdinand I declared himself king of Hungary and Bohemia. Suleiman responded, with the support of Ferdinand’s main rival for the Hungarian succession, John Zápolya of Transylvania, by laying siege to Vienna in 1529.

    After twice repelling Ottoman attacks on Vienna but failing to reclaim much territory in Hungary or score any significant naval victories in the Mediterranean, Ferdinand was forced into a humiliating truce at Adrianople in 1547. The terms required him to relinquish most Hapsburg claims to Hungary and pay an exorbitant tribute for those small parts that remained nominally Hapsburg. They also referred to Charles V not as “Emperor,” but only as “King of Spain,” allowing Suleiman to proclaim himself the world’s true “Caesar.”28

    The Ottoman Empire’s victory cemented its position as a principal player in the European political landscape. The empire would continue to test the limits of its expansion in Central Europe and the Mediterranean for the next century and a half, even as it suffered a naval setback in the 1571 Battle of Lepanto. Only at the conclusion of the Great Turkish War in 1699 did the Hapsburg prince Eugene of Savoy manage to gain back most of Hungary and decisively reverse Ottoman expansion in Europe. The Ottomans’ protracted decline would last into the twentieth century.

  • 4. First half of 17th century — Hapsburgs vs. Sweden — WAR

    Period: First half of 17th century
    Ruling power: Hapsburgs
    Rising power: Sweden
    Domain: Land and sea power in northern Europe
    Outcome: Part of Thirty Years’ War (Swedish involvement, 1630–48)

    At the time of his election as Holy Roman emperor in 1619, Ferdinand II was the most powerful ruler in Central Europe. His empire, which carried the authority of the papacy, stretched from the Mediterranean to northern Germany. His ascent to power, however, coincided with one of the greatest threats the empire had ever faced: the rise of the Lutheran north. Ferdinand’s attempts to quash isolated cases of Lutheran rebellion and reassert Hapsburg rule would eventually grow into the Thirty Years’ War. They would also bring him into conflict with the region’s fastest-rising power, Sweden.

    During the first half of the seventeenth century, in response to nascent rebellions in the German northern provinces, several Protestant powers outside the Holy Roman Empire — including England and the Dutch Republic — volunteered to finance a militarily powerful Protestant state to confront imperial general Albrecht von Wallenstein in northern Germany. The first king to be given the chance was Christian IV of Denmark. Overmatched, Christian was driven all the way back to the Danish isles, leaving Holy Roman Emperor Ferdinand II even stronger and a ruling force throughout Germany and the rest of northern Europe. Wallenstein’s arrival at the shores of the Baltic Sea, along with his plan to assert control in the Baltic by building a Hapsburg northern fleet, seriously alarmed the king of the region’s most rapidly rising power, Sweden.

    Through wars with Denmark, Russia, and Poland, Swedish king Gustavus Adolphus established himself as one of Europe’s most capable commanders. Through a combination of economic growth, military innovation, and territorial expansion, Gustavus transformed Sweden from a poor, backward state into one of Europe’s most powerful empires. Between 1590 and 1630, Sweden’s small provincial army grew from 15,000 into a force of 45,000.29 Innovations in the use of artillery and a conscription system (Europe’s first) helped to build a well-oiled military machine.30 His decisive victories over Russia in 1617 and the Polish-Lithuanian Commonwealth in 1625 allowed Sweden to consolidate its control of the Baltics. After capturing a slice of Poland in 1629, Sweden controlled almost “every port of consequence on the southern shore of the Baltic.”31

    The challenge of Sweden’s expansionism was not lost on the Hapsburg general. As English historian Samuel Gardiner observes, Wallenstein “had long been alarmed at the danger which threatened him from Sweden . . . for no man could expect that Gustavus would look on quietly, whilst a great military power was forming on the southern coast of the Baltics.”32 According to historian Peter Wilson, Wallenstein “regarded the imperial navy plan as purely defensive,” as a means of protecting Hapsburg dominance in northern Europe, for he “genuinely feared Swedish intervention.”33

    What the Hapsburgs considered a defensive measure proved far more provocative than planned. Gustavus lobbied for armed intervention in Germany on the grounds that the Hapsburgs were seeking to contain Swedish growth and constituted an imminent threat to Swedish security. Gustavus began to see a military standoff as “inevitable.”34 According to Brendan Simms, Gustavus argued before the Swedish Rijkstag that it would be best “to act pre-emptively in order to ‘transfer the seat and burdens of war to a place which is subject to the enemy.’”35 In 1627, he told his nobles: “As one wave follows another, so the popish league comes closer and closer to us. They have violently subjugated a great part of Denmark, whence we must apprehend that they may press on into our borders, if they be not powerfully resisted in good time.”36 As do many rising powers facing containment by an established power, Gustavus accused his enemy of precisely what he was about to do: pursue expansion and make military threats.

    Though motivated primarily by security interests, Gustavus solicited financial support by declaring himself the Protestants’ champion against the Catholic empire. This approach won him funding from around Europe. Paris, seeking to check Hapsburg power and wishing to maintain influence in a potential postwar order dominated by Sweden, also offered significant support.37 And so, according to historian Michael Roberts, “the Protestant cause became Sweden’s cause too; and the north German coastland became a Swedish interest.”38 Gustavus began his assault at Usedom, near the Polish-German border, in July 1630. The Swedes enjoyed early successes, taking Pomerania and moving inland. Gustavus’s ambition grew along with his power: he determined to “emasculate the emperor” and “ensure the emperor was never in a position to pose a danger again.”39

    Although Gustavus himself was killed in action, Sweden won decisive victories, most notably at the Battle of Wittstock in 1636. During the war, Swedish troops occupied half of Germany, and its triumphs were reflected in a favorable settlement at the 1648 Peace of Westphalia. Sweden became the most powerful country in northern Europe and the third-largest country on the Continent (behind Russia and Spain). What historians call Sweden’s Age of Greatness lasted into the early eighteenth century.


  • 5. Mid-to-late 17th century — Dutch Republic vs. England — WAR

    Period: Mid-to-late 17th century
    Ruling power: Dutch Republic
    Rising power: England
    Domain: Global empire, sea power, and trade
    Outcome: Anglo-Dutch Wars (1652–74)

    By the time the Dutch Republic was granted full recognition of its independence at the 1648 Peace of Westphalia, it had already emerged as Europe’s preeminent trading power. Its dominance of the seas and nascent colonial empire soon brought the republic into conflict with the English, who expanded their holdings in North America and their trading presence in the East Indies. Over several Anglo-Dutch wars at sea, the Dutch Republic’s dominance held, continuing until the two countries joined forces in the 1688 Glorious Revolution.

    With trading posts across the Silk Road, South America, West Africa, Japan, and the Pacific islands, as well as colonies in India and what later became New York, the Dutch Republic in the mid-seventeenth century was the world’s leader in international commerce. It used this power to construct a “borderless” world order, which enabled the tiny Netherlands to translate high productivity and efficiency into outsized political and economic power. Thus, lucrative trading routes gave the publicly owned Dutch East India Company a leading role in the global spice trade.

    Arguably the Continent’s most advanced seafaring people, the Dutch built a navy to match their massive overseas trading empire. It would not be long, however, before England, seeking to expand its own share of trade and control of the seas, established rival colonies on the American eastern seaboard. The English also began clawing for access to the spice trade with their own East India Company, while expanding their naval fleet (from 39 major ships in 1649 to 80 by 1651) to protect English shipping. By the 1650s, England’s military manpower (which had remained at roughly 20,000 to 30,000 men from 1470 to 1600) had more than doubled, to 70,000, and — in the wake of the English Civil War — became substantially more professional.40

    England’s designs on Dutch economic supremacy were unmistakable. Midway through the coming succession of wars, English general George Monck would say of fighting the Dutch: “What matters this or that reason? What we want is more of the trade the Dutch now have.”41 As historian J. R. Jones explains, “Aggressive foreign and mercantile policies” were also a way in which Charles II’s ministers “increased the powers and enhanced the authority of the crown.”42

    Dutch officials were gravely concerned about what they correctly perceived as England’s relentless pursuit of both mercantile power and the military means to defend it. As historian Paul Kennedy puts it, Dutch power was “firmly anchored in the world of trade, industry, and finance.”43 Unchecked, England could roll back Dutch control of the seas and threaten the tiny nation’s great power status.44

    Thus an ostensibly economic conflict became a geopolitical one. According to political scientist Jack Levy, this period was characterized by “the transformation of the commercial rivalry into a strategic rivalry that escalated to war . . . Although some interpret the first two Anglo-Dutch naval wars as ‘purely commercial,’ a purely economical explanation is misleading. The escalatory potential of the economic conflict in fact owed much to the close connection between economic and strategic issues.”45 Historian George Edmundson agrees, writing that each of the two nations was “instinctively conscious that its destiny was upon the water, and that mastery of the seas was a necessity of national existence.”46

    In 1651, the Dutch rejected English attempts at a treaty to unite against the continental Catholic powers, an agreement that may have been intended to gain access to Dutch trade. In response, an increasingly confident English Parliament passed the first Navigation Act, prohibiting any European imports to England carried by third-party ships, and barring foreign ships from carrying imports to England or its colonies from Asia, Africa, or America. The target of this legislation was no secret in either London or The Hague: a large portion of Dutch shipping focused on exactly this sort of activity.

    Describing England’s actions, sociologist Immanuel Wallerstein explains that “since the Dutch were in fact hegemonic, there were only two possible ways of enhancing English commerce: state assistance to English merchants or state constraint on foreign merchants . . . It is difficult to see how a military test of strength could have been avoided. The provocation to the Dutch was too great, even if the English thought they were being defensive.”47 Tensions boiled over the following year in the North Sea, when a confrontation led England to declare war, beginning the first of three Anglo-Dutch naval wars between 1652 and 1674. Though the conflicts resulted in England’s acquisition of New York and the dramatic growth of its navy (adding more than two hundred ships between Charles I’s 1649 execution and the Restoration in 1660),48 the Dutch navy emerged as Europe’s mightiest, inflicting a severe defeat on the English with the 1667 Raid on the Medway.

    In the end, Dutch sea and trade supremacy held firm, and the Anglo- Dutch rivalry dissolved with the invasion of Britain by Dutch prince William of Orange and the ensuing Glorious Revolution in 1688. The two nations went on to make common cause against William’s archenemy, France’s Louis XIV.

  • 6. Late 17th to mid-18th centuries — France vs. Great Britain — WAR

    Period: Late 17th to mid-18th centuries
    Ruling power: France
    Rising power: Great Britain
    Domain: Global empire and European land power
    Outcome: Nine Years’ War (1689–97), War of the Spanish Succession (1701–14), War of the Austrian Succession (1740–48), and Seven Years’ War (1756–63)

    During the reign of Louis XIV, France became the “preeminent power” in Europe.49 Emboldened by its prosperous American colonies and its Glorious Revolution, however, Great Britain soon challenged French supremacy in a succession of wars. At first, both Britain’s strength and its struggles with France derived mainly from its alliance with the Dutch Republic. But as Britain continued to grow as a trading and naval power that threatened French continental and colonial preeminence, their conflict would stretch across the globe and end in the undisputed imperial hegemony of Great Britain.

    Despite Louis XIV’s dominant position in Europe by the late seventeenth century, his continual quest for absolute security for France brought him into conflict with a large countervailing coalition of European powers. Although technically at peace with his neighbors, Louis systematically strengthened his position in the 1680s by seizing buffer zones beyond his borders in Strasbourg, Luxembourg, and Casale. These gains were accompanied by a military buildup, indicating an ambition for further conquests. While already possessing Europe’s largest army (and by 1689, its largest navy as well), Louis reinforced French fortresses, prepared 36 battalions of infantry for service, and put another 140,000 men on notice.50

    His ambitions alarmed his neighbors. In 1686, the Dutch prince William of Orange encouraged the Hapsburg Holy Roman emperor Leopold I to form the League of Augsburg, a coalition of powers intended to check further French expansion. In September 1688, the French crossed the Rhine into Phillipsburg. William feared French influence over his father-in-law, the Catholic James II of England, many of whose subjects were disquieted by the prospect of a popish dynasty. He also knew that an England free of James could be a powerful ally in suppressing France’s rise. Less than six weeks after Louis crossed the Rhine, William invaded England, with the support of numerous English sympathizers. James fled, and in 1689 the Protestant William became king of England, alongside his wife, Queen Mary.

    In early 1689, the League of Augsburg mobilized in response to Louis’s crossing of the Rhine the previous autumn. Britain, now united with the Dutch Republic through shared leadership, assumed its place as one of the league’s central partners in the Nine Years’ War against France (1689–97). In the words of historians Derek McKay and H. M. Scott, William’s Glorious Revolution, as it came to be known, brought Britain “decisively on to the continental stage as a military power as well as a diplomatic and naval one.”51/p>

    According to historian Sir George Clark, William and his fellow Augsburg leader, the Holy Roman emperor, “regarded the war as an opportunity to reduce the power of France to a level which could be tolerable to the rest of Europe.”52 Although the war was ultimately successful in blunting Louis’s territorial designs, hostilities resumed in 1701 when William and the Hapsburgs rejoined forces in a bid to stop a misguided attempt by Louis to put a fellow Bourbon on the Spanish throne. The alliance was unable to prevent Louis’s grandson from assuming the throne, but it succeeded in forcing Louis to cede territory in the New World to Britain in the Treaty of Utrecht.

    Partly as a result of its Utrecht acquisitions, Britain reaped substantial economic benefit from its colonies during the 1700s. “Exports to North America rose from a yearly average of £525,000 in the late 1720s to just over £1 million twenty years later,” according to historian Lawrence James.53 The British also benefited from a set of financial reforms based on the Dutch model.54 Britain’s growth had its French competitors greatly concerned. “French officials,” as historians Robert and Isabelle Tombs write, “were ‘stupefied’ and ‘obsessed’ by British financial power.”55 This economic growth also proved to be a prelude to further military expansion: after the War of the Spanish Succession, the British naval fleet exceeded the strength of the French and Spanish navies combined.56 Britain’s financial power allowed it to raise money quickly in times of conflict. Despite France’s formidable land forces, Britain “managed when necessary to outspend France, devoting as much as five times the proportion of its GNP to war as its enemy,” as Robert and Isabelle Tombs note.57

    The rapid growth of Britain’s colonial empire in North America led to increasing conflict with the French over rights to trade and territory. Thus the 1740 War of the Austrian Succession (a Central European conflict in which France fought to undermine its longtime enemy the House of Hapsburg, while Britain fought to defend it) spilled over onto the American continent. While the 1748 peace at Aix-la-Chapelle ended that conflict with victory for the Hapsburgs and Britain, it did nothing to abate the French-British rivalry, which, according to the English historian Lawrence James, “persisted and deepened after 1748. The French remained convinced that their antagonist’s long-term aim was to stifle their trade and expropriate their colonies.”58 In fulfillment of France’s fears, Britain underwent a massive military expansion during and after the War of the Austrian Succession, increasing military spending between 1740 and 1760 by 500 percent, while France managed only a 150 percent increase.59

    In 1756, the French and British rivalry reignited in the Seven Years’ War. Britain’s decisive victory over France at the conclusion of that conflict, in 1763, led to a wholesale rearrangement in the balance of power in North America and Europe. Even though it would soon lose much of its American empire — in no small part due to French intervention — Britain had overtaken France as Europe’s greatest imperial power, a position it would maintain into the Napoleonic era.

  • 7. Late 18th and early 19th centuries — United Kingdom vs. France — WAR

    Period: Late 18th and early 19th centuries
    Ruling power: Great Britain/United Kingdom
    Rising power: France
    Domain: Land and sea power in Europe
    Outcome: French Revolutionary Wars (1792–1802) and Napoleonic Wars (1803–15)

    Through ingenuity and control of the seas, Great Britain had, by the end of the eighteenth century, pulled ahead of its rivals to become one of Europe’s leading industrialized nations. But beginning with the French Revolution, a reinvigorated French military machine would rise again. Under Napoleon, France would take over much of continental Europe and threaten British supremacy, leading Britain and France into violent confrontation. By funding anti-Napoleonic forces in Europe and fighting brilliantly at sea, however, Britain managed to avoid invasion and hasten Napoleon’s eventual fall from power.

    During the 1780s, Britain’s wave of innovation led to domestic industrialization and booming colonial trade, with merchant shipping doubling between 1782 and 1788.60 By 1793, Britain could rely on 113 ships of the line to protect these trade interests, dwarfing the 76 equivalent ships of Europe’s premier mercantile economy, France.61 It would not be long, however, before the small island nation faced a fresh challenge from its great rival across the English Channel.

    Though the French economy remained backward in the years following the 1789 revolution, its extraordinary political developments and surging militarism threatened the European status quo.62 Anxious over the increasingly radical revolution and the safety of King Louis XVI and his wife, Marie-Antoinette, Holy Roman Emperor Leopold II and Prussia’s King Frederick William II issued the Declaration of Pillnitz in 1791, which called on European powers to declare war on France if the royals were endangered. Intended as a warning, the declaration arguably accelerated conflict, as French radicals, feeling threatened, declared war the following April and successfully invaded the Austrian Netherlands.

    That campaign struck fear across monarchic Europe, especially because France “proclaimed new war aims calculated to alienate and alarm not only monarchs, but the entire social hierarchies upon which their power rested.”63 Corresponding transformations in French military organization, ideology, and aggressiveness confirmed European anxiety that the country’s radicalism would not be contained. France’s shift from aristocratic to popular military leadership opened commissions to new talent and increased enthusiasm for military service; in 1792 alone, the army gained 180,000 new recruits, and a program of universal conscription the next year swelled the ranks — and revolutionary fervor — further.64

    This marriage of rising military power and radical politics instilled particular panic in Britain. In a 1793 message to the House of Commons, King George III requested “a further augmentation of his forces by sea and land,” as a means of opposing “views of aggrandizement and ambition on the part of France, which would be at all times dangerous to the general interests of Europe, but are peculiarly so, when connected with the propagation of principles which . . . are utterly subversive of the peace and order of all civil society.”65 According to the British historian William Doyle, while the French invasion of the Low Countries had put Britain on notice, the execution of King Louis XVI in January 1793 was the final straw, galvanizing the British to action and prompting Britain to “engineer a grand anti-French coalition.”66 By early 1793, this coalition of European powers was at war, attempting to reverse French territorial gains. These efforts proved unsuccessful: France would augment its territory in the 1790s through annexations in the Netherlands, northern Italy, and through the brief acquisition of America’s Louisiana Territory.

    British fears of French expansionism rose to the level of existential threat when Napoleon Bonaparte seized power in the 1799 Coup of 18 Brumaire and embarked on a campaign of European domination.67 Specifically, Napoleon was known to have told the French Directory in 1797 that France “must destroy the English monarchy, or expect itself to be destroyed by [it],” and he pledged to “annihilate England. That done, Europe is at our feet.”68 Britain took these threats seriously. “We are here in daily expectation that Bonaparte will attempt his threatened invasion,”69 George III confided in 1803. Even when Napoleon failed to invade in the near term, his advances on the Continent reinforced Britain’s long-standing conviction that its security required prevention of a hegemonic land power in Europe whose lack of rivals would allow it to divert resources toward a fleet. Prime Minister William Pitt responded with a strategy that, as military historian Michael Leggiere argues, aimed not only “to restore the balance of power in Europe by forcing France to surrender conquests such as the Low Countries,” but also to leave Britain as “master of the seas and with a clear monopoly on global trade.”70

    Fortunately for Britain, Napoleon never developed a navy that could supplant British dominance at sea. In 1805, Vice Admiral Horatio Nelson defeated the French fleet at Trafalgar, ending Napoleon’s hopes of invading Britain and keeping Britain secure in its role as financial backer of Napoleon’s European enemies. Thereafter, as Napoleon continued expanding on the Continent while incurring massive public debt, Britain’s economic and diplomatic advantages became increasingly undeniable, and London became the great hope of anti-Napoleonic Europe. As Paul Kennedy explains, “The government in Paris could never be certain that the other continental powers would permanently accept the French imperium so long as Britain — offering subsidies, munitions, and possibly even troops — remained independent.”71 Shaken by his first major land defeat in an ill-advised invasion of Russia in 1812, Napoleon went on to further large-scale defeats and met his final demise at the hands of a British-led coalition at Waterloo in 1815.

  • 8. Mid-19th century — France and United Kingdom vs. Russia — WAR

    Period: Mid-19th century
    Ruling powers: French Empire (land) / United Kingdom (sea)
    Rising power: Russia
    Domain: Global empire, influence in Central Asia and eastern Mediterranean
    Outcome: Crimean War (1853–56)

    Throughout the first half of the nineteenth century, Russia instilled fear in Europe as it steadily gained territory and military power. France and the United Kingdom, as established players in global trade with territory and networks in the Middle East and southern Asia, were particularly alarmed by St. Petersburg’s recurring efforts to exploit the declining Ottoman Empire. These tensions reached their climax in the Crimean War, a conflict that vindicated British and French dominance and revealed the latent weakness behind Russia’s rise.

    Russia achieved highly generous settlements in the aftermath of the Russo-Turkish wars (1806–12 and 1828–29), adding to its protectorates in Eastern Europe and the Caucasus, and expanding its access to the Black Sea. These wars, along with Russian campaigns in Persia and Eastern Europe, contributed to a huge expansion of territory: Russia acquired all or part of modern-day Finland, Poland, Georgia, Azerbaijan, and Armenia in the late eighteenth and the first half of the nineteenth centuries alone, coming dangerously close to the centers of European power.72 As Russian territory grew, so did its military: already more than twice the size of either France’s or Britain’s by 1820, Russia’s army grew to be significantly larger than both combined by 1853.73

    With each advance, fears grew that Russia could threaten the global balance of power by making Europe’s “sick man” — as the tsar called the Ottoman Empire — a Russian protectorate.74 The 1829 Treaty of Adrianople, between St. Petersburg and Constantinople, convinced Lord Heytesbury, the British ambassador to Russia, that Russia would soon make the Ottomans as “submissive to the orders of the Tsar as any of the Princes of India to those of the [British East India] Company.”75 It was in this spirit that both Britain and France intervened diplomatically on the Ottoman side in the Egyptian-Ottoman War of 1831–33, fearing that a weakened Ottoman Empire might be vulnerable to Russian pressures.

    Russia’s repeated attempts to usurp Ottoman power and to assert influence in Eastern Europe convinced Britain that Russia intended, as historian Brendan Simms puts it, not only to “partition the Ottoman Empire, but to dominate Europe as a whole,”76 and to secure control of the Dardanelles, which would give its Russian Black Sea fleet a foothold in the Mediterranean. This so-called Eastern Question posed a strong threat to British naval dominance. Some in Britain even believed Russia might challenge British colonial power in India.77

    Henry Kissinger proposes one explanation for British and French anxiety: “Everything about Russia — its absolutism, its size, its globe-spanning ambitions and insecurities — stood as an implicit challenge to the traditional European concept of international order.”78 The anxiety Kissinger identifies was evident even among the general public in France and Britain. In one vivid example, a popular French travel publication at the time described Russia as possessing “inordinate and immense” ambition, with “the design to exercise a tyranny over other nations.”79 Not until it was tested in the crucible of war did either Russia or its competitors recognize that it was a “colossus with feet of clay.”80

    In 1853, Tsar Nicholas I demanded that Sultan Abdulmejid recognize a Russian protectorate over Orthodox subjects in Constantinople and the Holy Land. British diplomats tried to mediate the dispute, but ultimately failed to achieve a settlement agreeable to the Ottoman sultan. When diplomacy failed, the sultan declared war on Russia. The tsar quickly took the offensive, sending troops to occupy the Danube Principalities (modern-day Moldova and Romania) and building up his Black Sea fleet at Sevastopol, the capital of Crimea. After the Russians successfully destroyed an Ottoman fleet at Sinope, Britain and France had seen enough. Despite the tsar’s protestations to the contrary, both nations feared the collapse of the Ottoman Empire and the vacuum it would leave for Russian power to fill. For Britain, Russia’s capture of Constantinople would pose an intolerable threat to its position in the Mediterranean. Fear of Russian expansion united Britain and France in a joint undertaking that included sending a fleet into the Black Sea and issuing an ultimatum demanding that Russia withdraw from the Principalities. When Russia refused, France and Britain declared war and sent an expeditionary force to Crimea.

    Technical and organizational backwardness betrayed Russia in battle. The eventual defeat of Russian forces at Sevastopol shattered the illusion of Russian military superiority, boosted French and British prestige and confidence, and saved the ailing Ottoman Empire for another sixty-five years. As naval historian Adam Lambert concludes, “Britain, France and Russia fought on a global scale for mastery of Europe — a prize that went, temporarily, to the French — and mastery of the world, which the British retained for another two generations.”81

  • 9. Mid-19th century — France vs. Germany — WAR

    Period: Mid-19th century
    Ruling power: France
    Rising power: Germany
    Domain: Land power in Europe
    Outcome: Franco-Prussian War (1870–71)

    Under Napoleon III, France emerged, in historian Paul Kennedy’s words, “strong and confident”82 in the second half of the nineteenth century as Western Europe’s premier land power. But soon Otto von Bismarck of Prussia, a statesman of rare skill at the helm of a surging economy, pursued ambitions to create a united Germany and usurp France’s position. While Bismarck saw war as necessary to unite the German states, France embraced conflict as a means to limit Prussia’s prodigious rise. The one-year war vindicated Bismarck’s strategic foresight and cemented Germany’s status as a great and unified power.

    In 1850, France’s colonial empire stretched worldwide, from the Pacific Islands and the Caribbean to West Africa and Southeast Asia. Its domestic manufacturing economy was continental Europe’s most productive.83 Its military expenditures by 1860 exceeded any of its competitors’ aside from Russia, and its navy grew so large that, as Paul Kennedy notes, it “at times . . . caused alarm on the other side of the English channel.”84 Also by 1860, France’s recent military interventions in Crimea and the Second War of Italian Independence had established Paris as the Continent’s major security guarantor. That preeminence, however, would prove short-lived. Ten years later, Napoleon III faced one of the greatest military machines Europe had ever seen: Otto von Bismarck’s Prussia.

    After defeating Denmark in 1864 and Austria in 1866, Prussia put France, as historian Michael Howard notes, “in that most dangerous of all moods; that of a great power which sees itself declining to the second rank.”85 While Prussia in 1820 had only one-third the population of France, the annexations of the 1860s saw that proportion balloon to almost four-fifths by 1870. Bismarck also amassed, “thanks to the Prussian use of universal conscription — an army one-third larger than France’s.”86 A French historian would later claim that a force resembling the 1.2 million soldiers Bismarck fielded had not been seen “since the legendary armies of Xerxes.”87 Prussia’s industrial rise was just as formidable, growing from half of France’s iron and steel production in 1860 to overtake it ten years later.88 Bismarck also developed a rail transportation system to match. According to historian Geoffrey Wawro, these rapid developments “were alarming indicators that threatened a total eclipse of French power.”89 It is therefore no mystery why Prussia “dominated [French] foreign and domestic politics after 1866.”90

    Bismarck’s goal was to join his Prussian-dominated North German Confederation with the southern German states of Baden, Württemberg, Bavaria, and Hesse.91 Ever the master strategist, he concluded that a war against France, which would scare the independent south German states into Prussia’s arms, would be a vital step toward German unification. As Bismarck later claimed, “I did not doubt that a Franco- German war must take place before the construction of a United Germany could be realized.”92

    All Prussia had to do was provoke the war. Recognizing Napoleon’s alarm at Prussia’s rise to his east, Bismarck found an ideal opportunity to stoke French fear even higher by threatening to place a German prince from the House of Hohenzollern on the Spanish throne.93 France would then face German power on two sides.

    The Hohenzollern candidacy and the Ems Telegram (a half-true press dispatch that Bismarck had manipulated to suggest that there had been a confrontation between the Prussian king and the French ambassador) contributed to Napoleon’s decision to declare war on Prussia in July 1870. In so doing, France made a strategic error common to ruling powers: taking action it believes will prevent a rising power from surpassing its position but in fact hastening the very reversal of fortune it most fears. France remained confident in 1870 (incorrectly, as it turned out) that it could defeat that Prussian threat, but felt that it needed to fight a preventive war before Prussia rose further.94 Because the southern German states considered France the aggressor, they joined the North German Confederation, just as Bismarck had anticipated. “There can be no doubt,” Michael Howard contends, “that France was the immediate aggressor, and none that the immediate provocation to her aggression was contrived by Bismarck.”95 After a decisive victory, a unified Germany emerged with the strongest army on the Continent. It became, as Brendan Simms writes, “by any standard a colossus.”96 Thus a war that catapulted Bismarck to the ranks of the great statesmen but led to Napoleon’s capture and exile initially seemed as good an option for France as it did for Prussia.

  • 10. Late 19th and early 20th centuries — China and Russia vs. Japan — WAR

    Period: Late 19th and early 20th centuries
    Ruling powers: China and Russia
    Rising power: Japan
    Domain: Land and sea power in East Asia
    Outcome: First Sino-Japanese War (1894–95) and Russo-Japanese War (1904–5)

    Entering the final decade of the nineteenth century, two powers dominated the Asian continent: Qing Dynasty China, for centuries the predominant regional power, and the Russian Empire, a European great power with long-standing ambitions in the Asia-Pacific. But since the Meiji Restoration of 1868, both states had a new threat to fear in the rapidly modernizing island nation of Japan. By 1905, China and Russia had been chastened by two damaging wars against the ambitious Japan, and both had to contend with a new Pacific power whose growth showed no signs of slowing.

    Rapid economic growth and military advances facilitated Japan’s rise in the late nineteenth century: GNP almost tripled between 1885 and 1899, and military expenditures grew dramatically as Emperor Meiji built a formidable standing army and navy.97 In 1880, military expenditures accounted for 19 percent of the Japanese budget; by 1886, this figure had risen to 25 percent, and by 1890, 31 percent.98

    Japan’s increasing power heightened its leadership’s resentment toward its subordinate position in the region compared to Western powers and China, encouraging a “sense of urgency that they must act more energetically” to extend Japanese influence.99 Gains in military strength allowed the country’s leaders to seriously contemplate territorial expansion in the Pacific islands and on the Asian continent, which would be a direct challenge to Chinese hegemony and Russia’s well-known designs on the region. But to project power effectively, the Japanese needed a mainland foothold: the Korean Peninsula.

    Beginning in the 1870s, Japan’s evolving policies toward Korea served as a barometer of Tokyo’s increasing confidence and assertiveness as a rising power. At first, these policies focused primarily on promoting reforms to strengthen the Korean government and its institutions against Chinese intervention, extending Japan’s influence while gently drawing Korea away from Beijing. As historian of Japan Peter Duus writes, Korea’s strategic significance “was not merely its proximity to Japan but its inability to defend itself against outsiders . . . If Korea remained ‘backward’ or ‘uncivilized,’ it would remain weak, and if it remained weak, it would be inviting prey for foreign predators.”100 Yet by the eve of the Sino-Japanese War in 1894, historian Akira Iriye notes Japan’s objective “was no longer the maintenance of a balance between Japan and China, but the ejection of Chinese influence from the peninsula.”101

    Japan’s longer-term concerns about Western — and particularly Russian — influence in East Asia corroborated its growing assertiveness. The emperor feared that Russia might respond to Japan’s rapid rise by using its new Trans-Siberian Railway (begun in 1891) to intervene in the Korean Peninsula and perhaps even invade Japan.102 Yamagata Aritomo, a Japanese field marshal and prime minister, put it bluntly in 1893: “Neither China nor Korea is our enemy: it is Britain, France, Russia.”103

    In 1894, a Korean peasant rebellion called the Tonghak Uprising compelled Korea’s King Yi Myeong-bok to call upon Chinese troops for help in quelling the violence. Japan — unwilling to see its carefully cultivated influence eroded by Chinese intervention — sent its own troops, bringing them into direct conflict with the Chinese. Japan’s military preparedness stunned its opponents, as the emperor’s forces quickly expelled the Chinese from Pyongyang, scored an unexpected victory against China’s Beiyang naval fleet, and landed in southeast Manchuria, marching northwest into Chinese territory. The Sino-Japanese War concluded one year later in humiliation for Beijing with the Treaty of Shimonoseki, which acknowledged the independence of Korea (a nominal gesture that in reality turned Korea from a Chinese vassal to a Japanese vassal) and ceded Taiwan, the Pescadores Islands, and the Liaodong Peninsula to Japan.

    Japanese concerns about Russia’s intent to contain their power proved prescient. Unsettled by Japan’s smashing victory and the radical terms of the treaty, Russia, France, and Germany staged the Triple Intervention immediately following the settlement. The intervention, to which an embarrassed Japan reluctantly acquiesced, negated the treaty’s transfer of southeast Manchuria from China to Japan, keeping the threat of Japanese expansion off Russia’s doorstep.

    It also, however, hardened Japan’s determination to eliminate the Russian threat. “Ever since the humiliation of 1895,” writes historian J. N. Westwood, the Japanese government “had been deliberately preparing for an eventual war with Russia.”104 Japan’s preparations were dramatic, nearly tripling the emperor’s naval personnel in the ten years following the Sino-Japanese War, and increasing his army personnel ninefold.105 Reacting to Russia’s enlistment of French and German support in the Triple Intervention, Japan attempted to head off further European containment by concluding the Anglo-Japanese Alliance with Britain in 1902. Japan was determined to remove Russia from Manchuria.

    Unable to negotiate for the withdrawal of Russian troops, Japan carried out a surprise attack on the Russian fleet at Port Arthur (on the Manchurian coast) in February 1904. The attack ignited the year and- a-half-long Russo-Japanese War. Once again, Japanese forces won convincingly and achieved their objective of full Russian withdrawal from Manchuria at the resulting Treaty of Portsmouth. With Russia vanquished in Manchuria, Japan cleared away one more obstacle in its route to hegemony in the Pacific.

  • 11. Early 20th century — United Kingdom vs. United States — NO WAR

    Period: Early 20th century
    Ruling powers: United Kingdom
    Rising power: United States
    Domain: Global economic dominance and naval supremacy in the Western Hemisphere
    Outcome: No war

    In the last decades of the nineteenth century, US economic power rose to surpass the world’s foremost empire, the United Kingdom, and its growing fleet was a potentially troubling rival to the Royal Navy. As the United States began to assert supremacy in its own hemisphere, Britain, facing the challenges of more proximate threats and maintaining a far-reaching colonial empire, accommodated America’s rise. Britain’s concessions allowed the US to peacefully achieve dominance in the Western Hemisphere. This great rapprochement laid the groundwork for US-British alliances in two world wars and the enduring “special relationship” both nations now take for granted.

    In the last three decades of the nineteenth century, the United States had risen from the ashes of its civil war to become an economic colossus. American GDP, which exceeded Britain’s in the early 1870s, would by 1916 overtake the combined economy of the entire British Empire.106 Between 1890 and 1914, a rapidly developing United States tripled British levels of energy consumption and iron and steel production, all key measures of industrialization.107 As prosperity increased US confidence, Washington also became increasingly assertive in the Western Hemisphere, insisting on arbitrating disputes between European and Latin American states. This expanded regional role led to concerns over an impending great power conflict. In late 1895, fear that US involvement in a territorial dispute between Britain and Venezuela would lead to an Anglo-American war caused panic on the New York Stock Exchange.108 In January 1896, Prime Minister Lord Salisbury advised his finance minister that “a war with America, not this year but in the not distant future — has become something more than a possibility.”109

    The US Navy was still small compared to the Royal Navy, but it was growing (especially after the Spanish-American War and the ascendance of the hawkish Theodore Roosevelt to the presidency). American naval tonnage nearly tripled between 1900 and 1910.110 The First Lord of the Admiralty acknowledged in 1901 that “if the Americans choose to pay for what they can easily afford, they can gradually build up a navy, fully as large and then larger than ours.” With this reality in mind, he argued that “I would never quarrel with the United States if I could possibly avoid it.”111

    To the consternation of the British War Office, the Admiralty quietly exempted the US from the Two-Power Standard that committed the UK to maintaining a number of battleships equal to those of its next two largest competitors combined. The Admiralty was preoccupied with threats closer to home, and did its best to avoid contingency planning for a war with America. In 1904, the First Sea Lord told his civilian superior at the Admiralty that Britain should “use all possible means to avoid such a war,” because “under no conceivable circumstances” could it “escape an overwhelming and humiliating defeat by the United States.” It was therefore “an utter waste of time to prepare for it.”112

    Salisbury expressed the regret felt by many in Britain for having failed to challenge the American threat earlier: “It is very sad, but I am afraid America is bound to forge ahead and nothing can restore the equality between us. If we had interfered in the Confederate Wars it was then possible for us to reduce the power of the United States to manageable proportions. But two such chances are not given to a nation in the course of its career.”113

    Rather than challenge America’s rise through war, the UK adapted, managing a “Great Rapprochement.” Facing more ominous and proximate threats elsewhere, stretching to defend its imperial possessions, and with no competitors to the US in the Western Hemisphere that it could enlist as allies, Britain had little choice but to accommodate the Americans. It deferred to what many British saw as unreasonable American demands over territorial disputes in Canada and Latin America, lucrative fishing rights, and control of the future Panama Canal. “By the end of 1903,” according to historian Anne Orde, “by a series of concessions for which the United States made no return, Britain had acquiesced in American supremacy in the Western hemisphere from Venezuela to Alaska.”114

    Britons would have been justified in resenting the lack of American gratitude for a century of “free security.”115 But London’s willingness to compromise helped to heal long-standing hostility between the two nations, enough that when war came in 1914, the US could be an essential source of materiel and finance for Britain. American loans and support during World War I, and Washington’s eventual entry into the war as a British ally, proved decisive in defeating Germany.

  • 12. Early 20th century — United Kingdom (supported by France, Russia) vs. Germany — WAR

    Period: Early 20th century
    Ruling powers: United Kingdom, supported by France and Russia
    Rising power: Germany
    Domain: Land power in Europe and global sea power
    Outcome: World War I (1914–18)

    After unification under Bismarck, Germany was the leading military and economic power in continental Europe. It rose further to threaten British industrial and naval supremacy, and to risk unsettling the European balance of power. Though initially intended to earn respect, Germany’s surging sea power touched off a fierce naval race with Britain. Anglo-German rivalry, along with a second Thucydides Trap between Germany and a rising Russia to its east, played a vital role in transforming a regional Balkan conflict into World War I.

    Between 1860 and 1913, Germany’s share of global manufacturing ballooned from 4.8 percent to 14.8 percent, surpassing its chief competitor, the United Kingdom, whose share sank from 19.9 percent to 13.6 percent.116 Prior to unification in 1870, Germany had produced only half the steel Britain did; by 1914, it produced twice as much as Britain.117 By the 1880s, Bismarck had obtained colonial possessions in Africa, as well as trading outposts in China, New Guinea, and several islands in the South Pacific. These holdings in no way resembled the scale of the British or French empires, however, and Bismarck was not an enthusiastic imperialist. But the new German emperor, Wilhelm II, who dismissed Bismarck in 1890, was determined that his country become a “World Power” — a status that required a formidable navy.

    In the 1890s, German admiral Alfred Tirpitz set a course to rival Europe’s premier naval power, Britain. Though intended to secure Britain’s respect, Germany’s naval buildup frightened British leaders and sparked an intense arms race. The First Lord of the Admiralty, the Earl of Selborne, underlined this concern in 1902: “I am convinced that the great new German navy is being carefully built up from the point of view of war with us . . . [The British ambassador in Germany is convinced that] in deciding on a naval policy we cannot safely ignore the malignant hatred of the German people or the manifest design of the German Navy.”<118

    Germany’s new fleet affected not only British naval policy but also its whole international outlook. As the historian Margaret MacMillan puts it, “The naval race which Germany intended as a means of forcing Britain to be friendly instead persuaded the latter not only to outbuild Germany but to abandon its preferred aloofness from Europe and draw closer to France and Russia.”119 Germany’s growing power raised the prospect of its being able to eliminate its continental rivals and control the coastline opposite Britain — which, along with any challenge to British naval supremacy, London considered an unacceptable threat.

    Berlin confronted a second Thucydidean dynamic in Russia’s growing strength. By around 1910, Russia had recovered from its earlier military defeat by Japan and a period of simmering revolutionary unrest, and now seemed to be rising as a revitalized, modern military power right on Germany’s borders. In 1913, Russia announced the “grand program” for expanding its army, to be enacted the following year. It was expected that by 1917 the Russian army would outnumber Germany’s by three to one. French development of Russia’s strategic railways already threatened the entire German war plan. Germany’s plan for a two-front war entailed quickly defeating France before turning around to deal with the slow-moving Russian threat. By 1914, heavy French investment had allowed the development of a Russian railway system that would shorten its mobilization period to two weeks, as opposed to the six weeks assumed in the German plan.120

    Russia’s rapid rise, along with a general fatalism about an eventual European war, encouraged an aggressive attitude among Germany’s political and military leadership. Many espoused preventive war while there was still a chance to beat Russia, especially since a successful conflict might allow Germany to break out of its “encirclement” by Russia, France, and Britain.121 Berlin gave its infamous “blank check” to Vienna after the June 1914 assassination of an Austrian archduke in Sarajevo primarily because of the connected fears of its sole ally collapsing if Austria-Hungary did not crush its enemies in the Balkans and the prospect of being helpless in a future conflict against Russia.122

    Since the outbreak of hostilities, scholars have endlessly debated how to apportion blame for World War I; some even reject the question altogether.123 Though naming culprits is necessarily simplistic, a pair of Thucydidean rivalries (Germany and Britain, and Germany and Russia) bears primary responsibility for turning a regional conflict between Austria-Hungary and Serbia into a multiyear continental conflagration.

    In 1914, the simultaneous dynamics between London and Berlin, and between Berlin and Moscow, became interlocked. Germany’s determination to prop up its ally, forestall the menace of a rising Russia, and thus ensure its own survival led to its declaration of war against the tsar — and his ally, France. In threatening to crush France and overturn the European balance of power, Germany crossed a red line for Britain. In the words of historian Paul Kennedy, “So far as the British and German governments were concerned, the 1914–18 conflict was essentially entered into because the former power wished to preserve the existing status quo, whereas the latter, for a mixture of offensive and defensive motives, was taking steps to alter it. In that sense, the wartime struggle between London and Berlin was but a continuation of what had been going on for at least fifteen or twenty years before.”124 Amid a host of other causes for war, none was as destructive as Thucydides’s Trap.

  • 13. Mid-20th century — Soviet Union, France, and United Kingdom vs. Germany — WAR

    Period: Mid-20th century
    Ruling powers: Soviet Union, France, United Kingdom
    Rising power: Germany
    Domain: Land and sea power in Europe
    Outcome: World War II (1939–45)

    Adolf Hitler led a simultaneous recovery of Germany’s economic power, military strength, and national pride, abrogating the Treaty of Versailles and flouting the postwar order maintained by France and the United Kingdom. Seeking Lebensraum, or living space, Hitler methodically expanded Nazi dominance over Austria and Czechoslovakia. Recognizing his ambitions too slowly, France and the UK declared war only after Hitler’s invasion of Poland, unable to stop German domination of the Continent until millions of Soviet and American forces turned the tide at the end of World War II.

    Victorious in World War I, the ruling powers of France and the United Kingdom spent the 1920s rebuilding their economies and military strength, while Germany remained subordinate, its power stunted by the punitive conditions of the Treaty of Versailles. The treaty demanded severe economic reparations and imposed tight constraints on the German military, prohibiting it from having planes, tanks, and any more than 100,000 troops. Germany was forced to surrender its overseas colonies as well as 13 percent of its European territory (and 10 percent of its population), and to submit to Allied occupation of its industrial core, the Rhineland.125 Most damaging to German pride was the “war guilt” clause, which laid blame for the war squarely on Germany. While “bitterly resented by almost all Germans,”126 the so-called “slave treaty”127 nevertheless “left the Reich geographically and economically largely intact and preserved her political unity and her potential strength as a great nation.”128 Only twenty years after the Great War, Adolf Hitler would use that strength in a second attempt to overturn the European order.

    Hitler “focused relentlessly” on bringing about Germany’s rise.129 After his National Socialist Party won elections in 1933, Hitler moved to consolidate his power through extra-democratic means. He justified himself with a call to marshal “all German national energies” toward the singular objective of rearmament to secure his vision of Lebensraum for the German people: “He wanted the whole of central Europe and all of Russia, up to the Volga for German Lebensraum to secure Germany’s self-sufficiency and status as a great power,” as Paul Kennedy puts it.130 The military buildup was rapid. When Hitler became chancellor, France and Britain together spent twice as much on defense as Germany. In 1937, Germany reversed the ratio, spending twice as much on defense as France and Britain combined.131 Germany’s steep rearmament was exemplified by its production of military aircraft: in 1933, Germany produced just 368 planes, but by 1938 it had increased production to 5,235, more than the combined output of France and Britain.132 The German army expanded from 39 divisions in 1936 to 103 divisions in 1939, to a total of 2.76 million men.<133

    Germany’s rearmament was first met with a “supine”134 response from its future adversaries, who showed “little immediate recognition of danger.”135 Despite Winston Churchill’s dire and repeated warnings that Germany “fears no one” and was “arming in a manner which has never been seen in German history,” Prime Minister Neville Chamberlain saw Hitler as merely trying to right the wrongs of Versailles, and acquiesced to the German annexation of the Sudetenland at Munich in September 1938.136 Yet Chamberlain’s anxiety grew as Hitler’s decision to occupy the remainder of Czechoslovakia in March 1939 indicated his broader aims. Chamberlain asked rhetorically: “Is this the end of an old adventure, or is it the beginning of a new? Is this the last attack upon a small State, or is it to be followed by others? Is this, in fact, a step in the direction of an attempt to dominate the world by force?”137 France, meanwhile, as Henry Kissinger explains, “had become so dispirited that it could not bring itself to act.”138 Stalin decided his interests were best served by a non-aggression pact signed with Germany, which included a secret protocol for the division of Eastern Europe.139

    One week after agreeing to the pact with Stalin, Hitler invaded Poland, triggering the British and French to declare war on September 3, 1939. The Second World War had begun. Within a year, Hitler occupied France, along with much of Western Europe and Scandinavia. Britain was defeated on the Continent, although it fought off German air assaults. In June 1941, Hitler betrayed Stalin and invaded the Soviet Union. By the time Germany was defeated four years later, much of the European continent had been destroyed, and its eastern half would be under Soviet domination for the next forty years. Western Europe could not have been liberated without the United States, on whose military power it would continue to rely. The war Hitler unleashed was the bloodiest the world had ever seen.

  • 14. Mid-20th century — United States vs. Japan — WAR

    Period: Mid-20th century
    Ruling power: United States
    Rising power: Japan
    Domain: Land and sea power in Europe
    Outcome: World War II (1941–45)

    Imperial Japan, bolstered by decisive victories in the Sino- and Russo-Japanese wars and a growing sphere of influence that included Korea and Taiwan, became aggressively hegemonic in the twentieth century. As Japanese expansion, particularly into China, threatened the American-led “Open Door” order in the Pacific, the United States became increasingly hostile toward Japan in the 1930s. After the US sought to contain Japan by embargoing its raw material imports, Japan attacked Pearl Harbor, drawing the hitherto reluctant Americans into World War II.

    In 1915, Japanese prime minister Okuma Shigenobu used his country’s newfound leverage to levy “Twenty-One Demands” against the Republic of China for greater Japanese economic and territorial authority over the Asia-Pacific. These demands posed a deep challenge not only to China but also to the regional order established by America’s Open Door policy of 1899. Secretary of State Henry Stimson worried that Japan’s claims threatened this order and the American way of life that depended on it.140

    In pursuit of a “New Order in East Asia,” Japan launched an unprovoked campaign to seize Manchuria in 1931. This campaign extended into the heart of China, reaching its ruthless climax in the 1937 Rape of Nanking. Though the US viewed Japan’s aggression against an American ally with consternation, President Franklin Roosevelt initially refrained from acting, even as Japan bombed a US ship seeking to rescue Americans near Nanking.

    In the next few years, however, the US began to step up aid to China and imposed increasingly severe economic sanctions against Japan. Since the island nation depended almost totally on imports of critical raw materials such as oil, rubber, and scrap iron, and because it considered territorial expansion vital to the procurement of natural resources and to its future as a great power, Japan’s leadership viewed this containment as a mortal threat. As Japanese ambassador Kichisaburō Nomura told Washington on December 2, 1941, “The Japanese people believe . . . that they are being placed under severe pressure by the United States to yield to the American position; and that it is preferable to fight rather than to yield to pressure.”141

    As Japan negotiated with the Axis Powers in Europe, Vichy France, and the Soviet Union for settlements that would allow for easier territorial expansion in Southeast Asia, the US cut off negotiations with Japan. Washington, according to historian Richard Storry, became convinced that Japan was “redrawing the map of Asia so as to exclude the West.”142 As sanctions tightened, American ambassador to Tokyo Joseph Grew insightfully noted in his diary, “The vicious circle of reprisals and counter reprisals is on . . . The obvious conclusion is eventual war.”143

    FDR’s August 1941 oil embargo of Japan proved to be the final straw. As former State Department official Charles Maechling explains, “While oil was not the sole cause of the deterioration of relations, once employed as a diplomatic weapon, it made hostilities inevitable. The United States recklessly cut the energy lifeline of a powerful adversary without due regard for the predictably explosive consequences.”144 In desperation, Japanese leaders approved a plan to deliver a preemptive “knockout blow” against the US Pacific Fleet at Pearl Harbor, clearing the way to seize resource-rich territory in Southeast Asia and the Dutch East Indies. As scholar Jack Snyder notes, Japan’s strategy reflected its conviction that “if the sun is not ascending, it is descending,” and that war with the US was “inevitable” given America’s “inherently rapacious nature.”145

    Retrospectively, American statesmen realized the rashness of their oil embargo. As the later secretary of state Dean Acheson put it, America’s misreading of Japanese intentions was not of “what the Japanese government proposed to do in Asia, not of the hostility our embargo would excite, but of the incredibly high risks General Tojo would assume to accomplish his ends. No one in Washington realized that he and his regime regarded the conquest of Asia not as the accomplishment of an ambition but as the survival of a regime. It was a life-and-death matter to them.”146 Japan’s attack on Pearl Harbor was a partial success in the short term, and Japan went on to enjoy great tactical victories against America and Britain, but the conflict eventually led to its almost total destruction by 1945. Its wars in East Asia cost tens of millions of lives.

  • 15. 1940s-1980s — United States vs. Soviet Union — NO WAR

    Period: 1940s-1980s
    Ruling power: United States
    Rising power: Soviet Union
    Domain: Global power
    Outcome: No war

    In the aftermath of World War II, the United States emerged as the world’s undisputed superpower. It controlled half the world’s GDP, formidable conventional military forces, and a monopoly on the most destructive instrument of war mankind had ever built: the nuclear bomb. American hegemony, however, was soon challenged by its World War II ally the Soviet Union. Though often tense, the Cold War stands as one of history’s greatest successes in escaping Thucydides’s Trap. By developing vehicles for competition outside of armed conflict, the two powers peacefully managed the highest-stakes great power competition in history.

    Having liberated the nations of Eastern Europe from Nazi rule at enormous cost, the Soviets felt entitled to carve a sphere of influence out of the ruins of Eastern Europe in the wake of World War II. Deploying Soviet military advisers and intelligence officers to co-opt local politicians, build new Communist Parties, engineer coups, and suppress dissent, the Soviet Union constructed an empire stretching into the middle of Germany and, in Churchill’s words, from “Stettin in the Baltic to Trieste in the Adriatic, an iron curtain . . . descended across the Continent.”

    It soon became apparent to many US policymakers that the Soviet Union, as the historian John Gaddis writes, sought “not to restore a balance of power in Europe, but rather to dominate that continent as thoroughly as Hitler had sought to do.”147 With an overarching position in Europe, Stalin could easily spread his “revolutionary imperial” communism worldwide. Nine months after V-E Day, George Kennan’s Long Telegram of February 1946 — followed by Winston Churchill’s Iron Curtain speech less than two weeks later — identified Soviet communism as an existential threat to the West. Navy Secretary James Forrestal represented the views of many American policymakers when he wrote that Soviet communism “is as incompatible with democracy as was Nazism or Fascism because it rests upon the willingness to apply force to gain the end.”148

    By 1949, the Soviet Union had successfully broken the US nuclear monopoly by testing its own atomic bomb. Eight years later, the USSR launched Sputnik, the first artificial satellite sent into space, dealing a blow to America’s presumed preeminence in science and technology. The Soviet economy, meanwhile, had begun to surge. Industrial production increased 173 percent over prewar levels by 1950, and annual economic growth (at least as officially reported) averaged 7 percent between 1950 and 1970,149 prompting fears that the Soviet Union might rival and even surpass the US economically.150 Paul Samuelson’s best-selling 1960s textbook, Economics: An Introductory Analysis, projected that Soviet GNP would overtake that of the US by the mid-1980s.151 Though Samuelson’s prediction never came to pass, the USSR did overtake the US in two key areas: military spending and production of iron and steel, both in the early 1970s.152

    Responding to the challenge, the United States employed all of the traditional instruments of warfare short of bombs and bullets, and many untraditional instruments as well. This confrontation thus came to be known as the Cold War.153 Despite a number of close calls (for example, the Cuban Missile Crisis) and several proxy wars (in Korea, Vietnam, Afghanistan, and elsewhere), overt conflict between the two militaries was averted.154 Historians have offered various explanations for why the Cold War never went hot. Most credit the specter of nuclear destruction,155 while some emphasize the geographic distance between the US and USSR,156 or the growth of reconnaissance programs that minimized the likelihood of dangerous misunderstandings.157 Many point to the two countries’ mutual recognition of constraints on competition that allowed them to attack each other using all forms of war except direct conflict.158 Yet another factor that allowed the two powers to escape war was the culture of cooperation that developed around nuclear weapons, beginning with the SALT Treaty in 1972 and culminating with the Reagan-Gorbachev summits of the 1980s. These summits not only reduced the risk of a nuclear accident, but also built a baseline of trust.

    In time, the US approach — a strategy of containment sustained over four decades — succeeded. The contrast between the success of free-market democracies and the internal contradictions of command- and-control authoritarianism hollowed out the Soviet regime over several decades. Unable to provide both guns and butter, the Soviet Union collapsed in 1991, and the defining conflict of the late twentieth century ended without bloodshed.

  • 16. 1990s-present — United Kingdom and France vs. Germany — NO WAR

    Period: 1990s-present
    Ruling power: United Kingdom and France
    Rising power: Germany
    Domain: Political influence in Europe
    Outcome: No war

    At the conclusion of the Cold War, many expected that a newly reunified Germany would regress to its old hegemonic ambitions. While they were right that Germany was destined for a return to political and economic might in Europe, its rise has remained largely benign. An awareness of how Thucydides’s Trap has ensnared their country in the past has led German leaders to find a new way to exert power and influence: by leading an integrated economic order, rather than by military dominance.

    When West German chancellor Helmut Kohl broached the question of German reunification at the conclusion of the Cold War, leaders of Europe’s status quo powers — the UK and France — balked at the prospect of a newly powerful Germany. For many strategists, the division of Germany at the end of World War II was the enduring solution to the “German problem” that had been at the root of two world wars. NATO’s triple mission for Europe, went an oft-repeated quip, was “to keep the Soviets out, the Americans in, and the Germans down.”159

    Britain’s and France’s anxieties were easy to understand: a reunified Germany would be Western Europe’s most populous country and an economic powerhouse. Along these lines, the French ambassador to Germany argued in 1989 that reunification “would give birth to a Europe dominated by Germany, which no one, in the East or West, wants.”160 Prime Minister Margaret Thatcher took these concerns even further, privately telling President George H. W. Bush of her fear that “the Germans will get in peace what Hitler could not get in war.”161 To counter this perceived threat, Thatcher and President François Mitterrand discussed strengthening the alliance between Britain and France. Mitterrand, for example, contemplated “bilateral military and even nuclear cooperation with Britain as a counterbalance.”162 According to former diplomat and scholar Philip Zelikow and former secretary of state Condoleezza Rice, “Europeans, particularly the French, believed that any revival of German power had to go hand in hand with European structures that would keep the German state from endangering France.”163

    As the European leaders foresaw, Germany indeed was able to leverage its economic strength into a position as Europe’s strongest political voice, filling the power vacuum left by the collapse of the Soviet Union. Remarkably, however, this reemergence has so far occurred peacefully. It has also occurred, over time, with British and French support. So how did it happen that, as Henry Kissinger recently observed, “seventy years after having defeated German claims to dominating Europe, the victors are now pleading, largely for economic reasons, with Germany to lead Europe”?164

    Germany’s peaceful rise is mostly due to its broad strategy of assuaging European suspicions through open gestures of good faith and seeking interdependence with its former adversaries. Most importantly, German leaders consciously chose not to redevelop a military presence commensurate with the nation’s economic power.

    This new path became especially apparent as Germany achieved economic hegemony, becoming a dominant player in Europe’s integrated markets and leader of the Frankfurt-based European Central Bank. As former British trade minister Stephen Green notes, Germany channeled its power mainly into influencing Europe’s political economy: “In no sense has Germany shown any readiness to play any strategic role in the world of foreign affairs of the kind both the British and the French have taken for granted.”165 A strategy of integration, as international relations scholar Helga Haftendorn describes it, “was to compensate for Germany’s gains in power and sovereignty by emphasizing the importance of integrating this potential into a new Europe, creating a ‘Europeanized Germany’ rather than a ‘German Europe.’”166

    It is important to note, of course, that Germany’s pursuit of economic integration began prior to reunification.167 Furthermore, Germany’s decision to forgo a military expansion to match its economic clout was undoubtedly influenced by America’s presence as a regional security guarantor and stabilizing force in Europe. Whatever its origins, though, Germany’s approach ultimately proved reassuring to its former foes, demonstrating a new ethos characterized by policy analyst Hans Kundnani in The Paradox of German Power as “a strange mixture of economic assertiveness and military abstinence . . . In geopolitical terms, Germany is benign.”168

    Recently, instability caused by the fallout from the global financial crisis and an overwhelming surge of immigrants and refugees from Syria and the Middle East have called the existing European system — and German leadership — into question. Regardless of Europe’s future, however, or the historically unusual circumstances of America’s security presence on the Continent, Germany’s approach at the critical moment of power transition provides enduring and important lessons for powers seeking to avoid Thucydides’s Trap. Germany has learned that increasing defense spending to match economic development can easily beget conflict, and that continual gestures of goodwill are needed to overcome deep-seated fear between rival nations. Through stability, openness, integration with former adversaries, and a willingness to forgo more traditional shows of power, Germany has managed thus far to escape Thucydides’s Trap.

Footnotes — Thucydides's Trap Case File

1 Joseph Pérez, “Avance portugués y expansion castellana en torno a 1492,” in Las Relaciones entre Portugal y Castilla en la Época de los Descubrimientos y la Expansión Colonial, ed. Ana María Carabias Torres (Salamanca, Spain: Ediciones Universidad de Salamanca, 1994), 107.
2 The War of Castilian Succession was fought between 1475 and 1479 over the question of whether the Castile-Aragon union would be allowed to stand. If this Castilian civil war reaffirmed Isabella, who was married to Aragonian king Ferdinand, as the next Castilian queen, the union would remain. If supporters of Juana (who was married to Portuguese king Alfonso V) won, Castile would have unified with Portugal instead. Portugal, of course, fought on the side of bringing Juana to the throne rather than Isabella. Therefore, rather than understanding this as a Thucydides’s Trap scenario in which fear of rising Castilian power unifying with Aragon prompts Portuguese aggression, we understand this war as a Portuguese attempt to acquire Castile as its own inheritance.
3 Malyn Newitt, A History of Portuguese Overseas Expansion, 1400–1668 (London: Routledge, 2005), 56.
4 Christopher Bell, Portugal and the Quest for the Indies (London: Constable, 1974), 180.
5 Alexander Zukas, “The Treaty of Tordesillas,” in Encyclopedia of Western Colonialism Since 1450 (Detroit: Macmillan Reference, 2007), 1088.
6 Bell, Portugal and the Quest for the Indies, 183.
7 Stephen Bown, 1494: How a Family Feud in Medieval Spain Divided the World in Half (New York: Thomas Dunne Books, 2012), 146–47.
8 Considering how little knowledge anyone had of the geography of the Americas at the time, King John’s adamant stance against the pope’s line of demarcation can be hard to understand. By 1494, neither power knew definitively that the Americas existed at all, let alone that a part of modern-day Brazil lay to the east of the 46th meridian. However, Christopher Bell hypothesizes that Portuguese explorers in the Atlantic prior to 1494 may have actually sighted land when accidentally blown off course on an African voyage, and returned to tell the king about it. Therefore, when King John disputed the 1493 papal bulls, it is possible that “he already knew that there was land across the Atlantic in the southern hemisphere; that, whether it was islands or terra firma, it was suitable for colonization and that it was to be found in the neighbourhood of 36' W.” Bell, Portugal and the Quest for the Indies, 186.
9 Disney, A History of Portugal, 48.
10 Ferdinand Magellan’s 1521 circumnavigation showed that Columbus had not in fact found a westward route to the East Indies, but a new and vast American continent.
11 Bown, 1494, 155.
12 In fact, it was so effective that it inspired a second, similar treaty. In 1529, Portugal and Spain resolved differences over sovereignty in the Molucca Islands through the Treaty of Zaragoza — a second meridian line dividing Portuguese from Spanish territory, though this time in the Pacific.
13 Jonathan Hart, Empires and Colonies (Malden, MA: Polity Press, 2008), 28.
14 María J. Rodríguez-Salgado, “The Hapsburg-Valois Wars,” in The New Cambridge Modern History, 2nd ed., vol. 2, ed. G. R. Elton (New York: Cambridge University Press, 1990), 380.
15 Ibid., 378. Making war against Muslim “infidels” was a responsibility inherent in the title of Holy Roman Emperor. Francis’s ability to forecast the coming conflict lends credence to political scientist Dale Copeland’s claim that Francis deliberately launched a preventive war against the Hapsburg Empire to prevent it from the rising. See Dale Copeland, The Origins of Major War (Ithaca, NY: Cornell University Press, 2000), 215.
16 Henry Kamen, Spain, 1469–1714 (New York: Routledge, 2014), 65; Copeland, The Origins of Major War, 381.
17 John Lynch, Spain Under the Hapsburgs, vol. 1 (Oxford: Oxford University Press, 1964), 88.
18 Robert Knecht, Francis I (Cambridge: Cambridge University Press, 1982), 72.
19 Rodríguez-Salgado, “The Hapsburg-Valois Wars,” 400.
20 Brendan Simms, Europe: The Struggle for Supremacy (New York: Basic Books, 2013), 10.
21 Halil İnalcık, The Ottoman Empire: The Classical Age, 1300–1600 (London: Phoenix Press, 2001), 35.
22 Caroline Finkel, Osman’s Dream: The Story of the Ottoman Empire, 1300–1923 (New York: Basic Books, 2006), 58.
23 Andrew Hess, “The Ottoman Conquest of Egypt (1517) and the Beginning of the Sixteenth-Century World War,” International Journal of Middle East Studies 4, no. 1, 67; Colin Imber, The Ottoman Empire, 1300–1650 (New York: Palgrave Macmillan, 2009), 293.
24 Hess, “The Ottoman Conquest of Egypt,” 70.
25 Ibid., 55.
26 Richard Mackenney, Sixteenth-Century Europe: Expansion and Conflict (New York: Palgrave Macmillan, 1993), 243.
27 Simms, Europe, 11.
28 Imber, The Ottoman Empire, 54.
29 Geoffrey Parker, Europe in Crisis, 1598–1648 (Ithaca, NY: Cornell University Press, 1979), 70.
30 Ibid., 210–11.
31 Michael Roberts, “Sweden and the Baltic, 1611–54,” in The New Cambridge Modern History, 2nd ed., vol. 4, ed. J. P. Cooper (New York: Cambridge University Press, 1970), 392–93.
32 Samuel Rawson Gardiner, The Thirty Years’ War, 1618–1648 (London: Longmans, Green, 1912), 105.
33 Peter Wilson, The Thirty Years War: Europe’s Tragedy (Cambridge, MA: Harvard University Press, 2009), 431.
34 Erik Ringmar, “Words That Govern Men: A Cultural Explanation of the Swedish Intervention into the Thirty Years War” (PhD diss., Yale University, 1993), 157.
35 Simms, Europe, 15.
36 Michael Roberts, Gustavus Adolphus (London: Longman, 1992), 59–60.
37 Geoffrey Parker argues that Gustavus managed essentially to extort massive financial support from France out of fear that Swedish success might block France out of the postwar settlement: “France could not take the risk that Gustavus might achieve, without her help, a position of dominance from which the map of Germany might be redrawn . . . French envoys . . . promised Sweden 1 million livres annually for five years, to finance a war for ‘the safe-guarding of the Baltic and Oceanic Seas, the liberty of commerce, and the relief of the oppressed states of the Holy Roman Empire.’ The treaty, which was published immediately, together with a note that France had paid 300,000 livres on the spot, created a sensation . . . It was widely acclaimed as a masterstroke of Swedish diplomacy.” See Parker, Europe in Crisis, 219.
38 Roberts, “Sweden and the Baltic, 1611–54,” 392.
39 Wilson, The Thirty Years War, 462.
40 Paul Kennedy, The Rise and Fall of the Great Powers: Economic Change and Military Conflict from 1500 to 2000 (New York: Random House, 1987), 63, 56.
41 Charles Wilson, Profit and Power: A Study of England and the Dutch Wars (London: Longmans, Green, 1957), 107.
42 J.R. Jones, The Anglo-Dutch Wars of the Seventeenth Century (New York: Routledge, 1996), 8.
43 Kennedy, The Rise and Fall of the Great Powers, 67.
44 It is important to remember that both powers’ pre-Smithian understanding of mercantilist economics did not yet admit to the possibility of free trade leading to mutual benefit. F.L. Carsten explains that the Dutch were reacting to “the idea of the domination of the British seas against the system, or the lack of the system, which the Dutch called the principle of free seas and which they upheld wherever their commercial power was or could be expected to be supreme. Only after many years and after the opening of new possibilities did it begin to be realized that world commerce itself could be expanded and that two capitalist and competing states could thrive without destroying each other.” See E. H. Kossmann, “The Dutch Republic,” in The New Cambridge Modern History, 2nd ed., vol. 5: The Ascendancy of France, 1648–88, ed. F. L. Carsten (Cambridge: Cambridge University Press, 1961), 283.
45 Jack Levy, “The Rise and Decline of the Anglo-Dutch Rivalry, 1609– 1689,” in Great Power Rivalries, ed. William R. Thompson (Columbia: University of South Carolina Press, 1999), 176, 189.
46 George Edmundson, Anglo-Dutch Rivalry During the First Half of the Seventeenth Century (Oxford: Clarendon Press, 1911), 5.
47 Immanuel Wallerstein, The Modern World-System II: Mercantilism and the Consolidation of the European World-Economy, 1600–1750 (Berkeley: University of California Press, 2011), 77–78.
48 Wilson, Profit and Power, 78.
49 John A. Lynn, The Wars of Louis XIV, 1667–1714 (Harlow, UK: Longman, 1999), 17.
50 Kennedy, The Rise and Fall of the Great Powers, 99; Sir George Clark, “The Nine Years War, 1688–1697,” in The New Cambridge Modern History, 2nd ed., vol. 6: The Rise of Great Britain and Russia, 1688–1715, ed. J. S. Bromley, (New York: Cambridge University Press, 1970), 223.
51 Derek McKay and H. M. Scott, The Rise of the Great Powers, 1648–1815 (London: Longman, 1983), 46. The Glorious Revolution tends to refer not only to William’s deposal of James, but also to a range of constitutional reforms granting more power to Parliament. William was generally content to approve these, as his priority was to harness English resources for the war with France.
52 Clark, “The Nine Years War,” 230.
53 Lawrence James, The Rise and Fall of the British Empire (New York: St. Martin’s Press, 1996), 66.
54 John Brewer, The Sinews of Power: War, Money and the English State, 1688– 1783 (London: Unwin Hyman, 1989), xvii.
55 Robert Tombs and Isabelle Tombs, That Sweet Enemy: The French and the British from the Sun King to the Present (London: William Heinemann, 2006), 51.
56 James, The Rise and Fall of the British Empire, 58.
57 Tombs and Tombs, That Sweet Enemy, 45.
58 James, The Rise and Fall of the British Empire, 66.
59 Tombs and Tombs, That Sweet Enemy, 46.
60 Kennedy, The Rise and Fall of the Great Powers, 120.
61 David Chandler, The Campaigns of Napoleon (New York: Macmillan, 1966), 208.
62 In late-eighteenth-century France, economic progress to rival Britain’s, according to historian François Crouzet, “was almost completely lacking. This decisive British superiority in ingenuity and willingness to innovate is the basic fact which accentuated the structural discrepancy between the two economies during the second part of the eighteenth century.” See François Crouzet, Britain Ascendant: Comparative Issues in Franco-British Economic History (Cambridge: Cambridge University Press, 1990), 12.
63 William Doyle, The Oxford History of the French Revolution (Oxford: Oxford University Press, 2002), 197.
64 Ibid., 198, 204–5.
65 William Cobbet, ed., Cobbett’s Parliamentary History of England: From the Norman Conquest, in 1066, to the Year 1803, vol. 30 (London: T. C. Hansard, 1806), 239.
66 Doyle, The Oxford History of the French Revolution, 200–202.
67 Napoleon enlarged the French army to more than triple its 1789 levels by 1815. See Kennedy, The Rise and Fall of the Great Powers, 99.
68 Charles Downer Hazen, The French Revolution and Napoleon (New York: Henry Holt, 1917), 251–52.
69 Norman Longmate, Island Fortress: The Defense of Great Britain, 1603–1945 (London: Hutchinson, 1991), 291.
70 Michael Leggiere, The Fall of Napoleon (Cambridge: Cambridge University Press, 2007), 2.
71 Kennedy, The Rise and Fall of the Great Powers, 124.
72 Such a rate of expansion is hardly unprecedented in Russian history: Russia “expanded each year by an amount larger than the entire territory of many European states (on average, 100,000 square kilometers annually) from 1552 to 1917.” See Henry Kissinger, World Order (New York: Penguin Books, 2014), 53.
73 Correlates of War Project, “National Material Capabilities Dataset,” version 4, 1816–2007, -capabilities; J. David Singer, Stuart Bremer, and John Stuckey, “Capability Distribution, Uncertainty, and Major Power War, 1820–1965,” in Peace, War, and Numbers, ed. Bruce Russett (Beverly Hills, CA: Sage, 1972), 19–48.
74 Orlando Figes, The Crimean War: A History (New York: Metropolitan Books, 2010), 40.
76 Simms, Europe, 221.
77 Figes, The Crimean War, 48.
78 Kissinger, World Order, 50.
79 Astolphe de Custine, Letters from Russia, ed. Anka Muhlstein (New York: New York Review of Books, 2002), 647.
80 Alexander Polunov, Thomas Owen, and Larissa Zakharova, eds., Russia in the Nineteenth Century: Autocracy, Reform, and Social Change, 1814–1914, trans. Marshall Shatz (New York: M. E. Sharpe, 2005), 69.
81 Adam Lambert, The Crimean War: British Grand Strategy Against Russia, 1853– 56 (Manchester, UK: Manchester University Press, 1990), 27.
82 Kennedy, The Rise and Fall of the Great Powers, 120.
83 Ibid., 149.
84Ibid., 183.
85 Howard, The Franco-Prussian War, 40.
86 Wawro, The Franco-Prussian War, 19.
87 Howard, The Franco-Prussian War, 22.
88 Correlates of War Project, “National Material Capabilities Dataset.” See Singer, Bremer, and Stuckey, “Capability Distribution, Uncertainty, and Major Power War,” 19–48.
89 Wawro, The Franco-Prussian War, 19.
90 Simms, Europe, 241.
91 Jonathan Steinberg, Bismarck: A Life (New York: Oxford University Press, 2011), 281-82.
92 Otto von Bismarck, Bismarck, the Man and the Statesman, Being the Reflections and Reminiscences of Otto, Prince von Bismarck, Written and Dictated by Himself After His Retirement from Office, trans. A. J. Butler (New York: Harper & Brothers, 1898), 57.
93 There is scholarly debate over the extent to which Bismarck intended the Hohenzollern candidacy to lead to war against France. It is fairly widely agreed, however, that Bismarck did desire war and that the candidacy, whether through coincidence or master plan, formed “the centerpiece of this quest for a confrontation.” See S. William Halperin, “The Origins of the Franco-Prussian War,” Journal of Modern History 45, no. 1 (March 1973), 91.
94 Jasper Ridley, Napoleon III and Eugenie (New York: Viking, 1980), 561.
95 Howard, The Franco-Prussian War, 40.
96 Simms, Europe, 243.
97 Mitchell, International Historical Statistics, 1025.
98 See charts on Japanese military expenditure in J. Charles Schencking, Making Waves: Politics, Propaganda, and the Emergence of the Imperial Japanese Navy, 1868–1922 (Palo Alto, CA: Stanford University Press, 2005), 47 (1873– 1889); 104 (1890–1905).
99 Akira Iriye, “Japan’s Drive to Great-Power Status,” in The Cambridge History of Japan, vol. 5: The Nineteenth Century, ed. Marius Jansen (Cambridge: Cambridge University Press, 1989), 760–61.
100 Peter Duus, The Abacus and the Sword: The Japanese Penetration of Korea, 1895–1910 (Berkeley: University of California Press, 1995), 49.
101 Iriye, “Japan’s Drive to Great-Power Status,” 764.
102 S.C.M. Paine, The Sino-Japanese War of 1894–1895: Perceptions, Power, and Primacy (Cambridge: Cambridge University Press, 2003), 77.
103 Stewart Lone, Japan’s First Modern War: Army and Society in the Conflict with China, 1894–95 (London: St. Martin’s Press, 1994), 25.
104 J. N. Westwood, Russia Against Japan, 1904–05: A New Look at the Russo-Japanese War (Albany: State University of New York Press, 1986), 11.
105 Schencking, Making Waves, 104.
106 Adam Tooze, The Deluge: The Great War, America, and the Remaking of the Global Order, 1916–1931 (New York: Viking, 2014), 13.
107 Kennedy, The Rise and Fall of the Great Powers, 200–201.
108 Ernest May, Imperial Democracy: The Emergence of America as a Great Power (Chicago: Imprint Publications, 1961), 57-59.
109 Bourne, Britain and the Balance of Power in North America, 339.
110 Kennedy, The Rise and Fall of the Great Powers, 203.
111Bourne, Britain and the Balance of Power in North America, 351.
112 Aaron Friedberg, The Weary Titan: Britain and the Experience of Relative Decline, 1895–1905 (Princeton, NJ: Princeton University Press, 1988), 197.
113 Margaret MacMillan, The War That Ended Peace: How Europe Abandoned Peace for the First World War (London: Profile Books, 2013), 38.
114 Anne Orde, The Eclipse of Great Britain: The United States and British Imperial Decline, 1895–1956 (New York: Saint Martin’s Press, 1996), 22; Ernest R. May and Zhou Hong, “A Power Transition and Its Effects,” in Power and Restraint: A Shared Vision for the U.S.-China Relationship, ed. Richard Rosecrance and Gu Guoliang (New York: Public Affairs, 2009), 12-13.
115 In his description of “free security,” C. Vann Woodward notes that the “costly navy that policed and defended the Atlantic was manned and paid for by British subjects for more than a century, while Americans enjoyed the added security afforded without added costs to themselves.” C. Vann Woodward, “The Age of Reinterpretation,” American Historical Review 66, no. 1 (October 1960), 2.
116 Kennedy, The Rise and Fall of the Great Powers, 202.
117 Paul Kennedy, The Rise of the Anglo-German Antagonism, 1860–1914 (London and Boston: Allen & Unwin, 1980), 464.
118 Matthew S. Seligmann, Frank Nägler, and Michael Epkenhans, eds., The Naval Route to the Abyss: The Anglo-German Naval Race, 1895–1914 (Farnham, Surrey, UK: Ashgate Publishing, 2015), 137– 38.
119 MacMillan, The War That Ended Peace, xxvi.
120 By 1914, a quarter of all French investment went to a rapidly industrializing Russia. Hew Strachan, The First World War, vol. 1 (Oxford and New York: Oxford University Press, 2001), 19, 62–63.
121 Holger H. Herwig, The First World War: Germany and Austria-Hungary, 1914–1918 (London: Bloomsbury, 2014), 20–24.
122 The German emperor worried that he had been humiliated in not standing up to his enemies in recent crises and saw a good opportunity to end Russian influence in the Balkans, even if this led to war with Moscow. Herwig, The First World War, 21–24; MacMillan, The War That Ended Peace, 523.
123 For example, Christopher Clark, The Sleepwalkers: How Europe Went to War in 1914 (London: Allen Lane; New York: Penguin Books, 2012), xxi–xxvii, 561.
124 Kennedy, Anglo-German Antagonism, 470.
125 Margaret MacMillan, Paris 1919: Six Months That Changed the World (New York: Random House, 2003), 465.
126 Richard J. Evans, The Third Reich in Power, 1933–1939 (New York: Penguin, 2005), 4.
127 Kennedy, The Rise and Fall of the Great Powers, 288.
128 William Shirer, The Rise and Fall of the Third Reich: A History of Nazi Germany (New York: Simon & Schuster, 2011), 58.
129 Evans, The Third Reich in Power, 705.
130 Kennedy, The Rise and Fall of the Great Powers, 305; Antony Beevor, The Second World War (London: Weidenfeld & Nicolson, 2012), 5.
131 Stephen Van Evera, Causes of War: Power and the Roots of Conflict (Ithaca, NY: Cornell University Press, 1999), 95–96.
132 Kennedy, The Rise and Fall of the Great Powers, 324.
133 Zara Steiner, The Triumph of the Dark: European International History, 1933– 1939 (New York: Oxford University Press, 2011), 835.
134 Beevor, The Second World War, 4.
135 Gerhard Weinberg, A World at Arms: A Global History of World War II (New York: Cambridge University Press, 2005), 22.
136 Winston Churchill, Never Give In!: Winston Churchill’s Speeches, ed. Winston S. Churchill (New York: Bloomsbury, 2013), 102–3.
137 “Speech by the Prime Minister at Birmingham on March 17, 1939,” Yale Law School Avalon Project,
138 Kissinger, Diplomacy, 294.
139 See Beevor, The Second World War, 17–21.
140 Kennedy, The Rise and Fall of the Great Powers, 334.
141 US Department of State, Papers Relating to the Foreign Relations of the United States and Japan: 1931–1941, vol. 2 (Washington, DC: US Government Printing Office, 1943), 780.
142 Richard Storry, Japan and the Decline of the West in Asia, 1894–1943 (London: Macmillan, 1979), 159.
143Herbert Feis, The Road to Pearl Harbor: The Coming of the War Between the United States and Japan (New York: Atheneum, 1965), 248.
144 Charles Maechling, “Pearl Harbor: The First Energy War,” History Today 50, no. 12 (December 2000), 47.
145Jack Snyder, Myths of Empire: Domestic Politics and International Ambition (Ithaca, NY: Cornell University Press, 1993), 126, 5.
146Dean Acheson, Present at the Creation: My Years in the State Department (New York: Norton, 1969), 36.
147John Lewis Gaddis, The Cold War: A New History (New York: Penguin, 2005), 15.
148James Forrestal letter to Homer Ferguson, May 14, 1945. See Walter Millis, ed., The Forrestal Diaries (New York: Viking Press, 1951), 57.
149Wilfried Loth, “The Cold War and the Social and Economic History of the Twentieth Century,” in The Cambridge History of the Cold War, vol. 2, ed. Melvyn Leffler and Odd Arne Westad (New York: Cambridge University Press, 2010), 514.
150 Secretary of State John Foster Dulles began to worry that it would be “very difficult to stop Communism in much of the world if we cannot in some way duplicate the intensive Communist effort to raise productivity standards.” See H. W. Brands, The Devil We Knew: Americans and the Cold War (New York: Oxford University Press, 1993), 70.
151 Paul Samuelson, Economics: An Introductory Analysis, 6th ed. (New York: McGraw-Hill, 1964), 807.
152 Correlates of War Project, “National Material Capabilities Dataset”; Singer, Bremer, and Stuckey, “Capability Distribution, Uncertainty, and Major Power War,” 19–48.
153 Many scholars — from those in the “revisionist” school to respected cold warriors like George Kennan — have argued that the United States overreacted to the Soviet threat. Plenty of historical evidence supports this view. The Thucydides’s Trap, however, does not require that the ruling power’s perception of the rising power’s rise be rational or proportionate to the threat. It simply requires that the rising power be at least somewhat rising, and that its rise is sufficient to inspire fear in the ruling power. Both conditions are, in this case, well satisfied.
154 During the rare cases in which the two powers fought covertly, as when Soviet pilots flew bombing sorties over South Korea during the Korean War, they were loath to admit it for fear of the potentially devastating consequences of nuclear escalation.
155 See Campbell Craig and Fredrik Logevall, America’s Cold War (Cambridge, MA: Harvard Belknap, 2009), 357; Melvyn Leffler, For the Soul of Mankind (New York: Hill and Wang, 2007), 465; Gaddis, The Cold War, 261.
156 John Lewis Gaddis, The Long Peace: Inquiries into the History of the Cold War (New York: Oxford University Press, 1987), 225.
157 Ibid., 232.
158 See Graham Allison, “Primitive Rules of Prudence: Foundations of Peaceful Competition,” in Windows of Opportunity: From Cold War to Peaceful Competition in US-Soviet Relations, ed. Graham Allison, William Ury, and Bruce Allyn (Cambridge, MA: Ballinger, 1989).
159 Jussi M. Hanhimaki, “Europe’s Cold War,” in The Oxford Handbook of Postwar European History, ed. Dan Stone (Oxford: Oxford University Press, 2012), 297.
160 Andrew Moravcsik, The Choice for Europe: Social Purpose and State Power from Messina to Maastricht (Ithaca, NY: Cornell University Press, 1998), 407.
161 Philip Zelikow and Condoleezza Rice, Germany Unified and Europe Transformed: A Study in Statecraft (Cambridge, MA: Harvard University Press, 1995), 207.
162 Moravcsik, The Choice for Europe, 408.
163 Zelikow and Rice, Germany Unified and Europe Transformed, 47.
164 Jacob Heilbrunn, “The Interview: Henry Kissinger,” National Interest, August 19, 2015,
165 Stephen Green, Reluctant Meister (London: Haus Publishing, 2014), 299.
166 Helga Haftendorn, Coming of Age: German Foreign Policy Since 1945 (Lanham, MD: Rowman & Littlefield, 2006), 319.
167 As Martin Dedman notes, “The objective of safely incorporating a revived German economy into Western Europe, in the absence of any formal peace settlement with the defeated, belligerent former Germany, was solved through economic integration: the creation of common markets originally in coal and steel in 1951 and in industrial goods in 1957. This meant that the recovery of German economic power did not pose a political or military threat to Europe in the 45 years following World War II (whereas Japan’s rise to economic superpower status has alarmed its Asian neighbours).” See Martin Dedman, The Origins and Development of the European Union, 1945–2008 (New York: Routledge, 2009), 2.
168 Hans Kundnani, The Paradox of German Power (London: C. Hurst, 2014), 102–3, 107.