Nuclear Issues

The defining question about global order for this generation is whether China and the United States can escape Thucydides’s Trap. The Greek historian’s metaphor reminds us of the attendant dangers when a rising power rivals a ruling power—as Athens challenged Sparta in ancient Greece, or as Germany did Britain a century ago. Most such contests have ended badly, often for both nations, a team of mine at the Harvard Belfer Center for Science and International Affairs has concluded after analyzing the historical record. In 12 of 16 cases over the past 500 years, the result was war. When the parties avoided war, it required huge, painful adjustments in attitudes and actions on the part not just of the challenger but also the challenged.

Most histories of post-1945 U.S. grand strategy focus on containment of the Soviet Union and U.S. efforts to promote political and economic liberalization. A closer look reveals that "strategies of inhibition"—attempts to control nuclear proliferation—have been a third central pillar of U.S. grand strategy for several decades.

A prominent model of nuclear proliferation posits that a powerful patron state can prevent a weaker ally from proliferating by providing it with security guarantees. The history of West Germany's pursuit of the bomb from 1954 to 1969 suggests that a patron may also need to threaten the client state with military abandonment to convince it not to acquire nuclear weapons.

In the United States and Europe, many believe that the best way to prevent Russia’s resumption of its historic imperial mission is to assure the independence of Ukraine. They insist that the West must do whatever is required to stop the Kremlin from establishing direct or indirect control over that country. Otherwise, they foresee Russia reassembling the former Soviet empire and threatening all of Europe. Conversely, in Russia, many claim that while Russia is willing to recognize Ukraine’s sovereignty and territorial integrity (with the exception of Crimea), Moscow will demand no less than any other great power would on its border. Security on its western frontier requires a special relationship with Ukraine and a degree of deference expected in major powers’ spheres of influence. More specifically, Russia’s establishment sentiment holds that the country can never be secure if Ukraine joins NATO or becomes a part of a hostile Euro-Atlantic community. From their perspective, this makes Ukraine’s nonadversarial status a nonnegotiable demand for any Russia powerful enough to defend its national-security interests.

When do states acquire nuclear weapons? History shows that only two types of states decide that the bomb is essential to their security: 1) very powerful states; and 2) weak states that lack ironclad security guarantees.

Policymakers have long focused on preventing nuclear weapons proliferation by controlling technology. Even developing countries, however, may now possess the technical ability to create nuclear weapons. The history of gas centrifuge development in twenty countries supports this perspective. To reduce the demand for nuclear weapons, policymakers will have look toward the cultural, normative, and political organization of the world.