Nuclear Issues

Earlier this month, South Korean President Yoon Suk-yeol set off alarms. In an off-the-cuff remark, he warned that Seoul might need to develop nuclear weapons—or demand redeployment of U.S. nuclear arms to the Korean Peninsula—to counter North Korean nuclear threats. In doing so, Yoon spotlighted a popular view once reserved for hawkish commentators, defense intellectuals, and former military officials. Keeping nuclear weapons out of South Korea will ultimately be a U.S. responsibility that requires addressing both the deteriorating security environment and the domestic drivers underlying Yoon’s statement.

 Stephen Walt decided to look back to see if 2022 had gone according to his expectations. In his last column of 2021, he had described "Biden’s 2022 Foreign-Policy To-Do List." What did he get right, what did he get wrong, and how well did the Biden administration perform?

Stephen Walt provides A realist POV on the war in Ukraine, competition with China, COVID, and more in the second part of an interview with Foreign Policy Editor-in-Chief Ravi Agrawal.

A quarter-century ago, China conducted what it called “missile tests” bracketing the island of Taiwan to deter it from a move toward independence by demonstrating that China could cut Taiwan’s ocean lifelines. In response, in a show of superiority that forced China to back down, the United States deployed two aircraft carriers to Taiwan’s adjacent waters. If China were to repeat the same missile tests today, it is highly unlikely that the United States would respond as it did in 1996. If U.S. carriers moved that close to the Chinese mainland now, they could be sunk by the DF-21 and DF-26 missiles that China has since developed and deployed. This article presents three major theses concerning the military rivalry between China and the United States in this century.

As the best documented major crisis in history, in substantial part because Kennedy secretly taped the deliberations in which he and his closest advisers were weighing choices they knew could lead to a catastrophic war, the Cuban missile crisis has become the canonical case study in nuclear statecraft. Over the decades since, key lessons from the crisis have been adapted and applied by the successors of Kennedy and Khrushchev to inform fateful choices.

Although Russia has relied exclusively on conventional weapons for its invasion of Ukraine, behind the scenes lurks Moscow’s massive nuclear arsenal. Hours before Russian forces crossed into Ukraine, Russian President Vladimir Putin reminded the world that his country was “one of the most powerful nuclear states” and that anyone who interfered with his war in Ukraine or threatened Russia directly would face “consequences that you have never faced in your history.” Three days later, as global outrage grew, Putin ordered Russia’s nuclear forces to a higher level of readiness. Even without these explicit threats, Russia’s nuclear deterrent would have prevented Western countries from intervening in Ukraine. Beyond supplying Kyiv with anti-armor and light air defense weapons, they will not come to Ukraine’s defense for fear of nuclear escalation, as U.S. President Joe Biden and other NATO leaders have made abundantly clear. Now that Putin’s attempts to seize Kyiv have been thwarted, there is a risk he will use tactical nuclear weapons to bring Ukraine to its knees. And while this scenario remains unlikely, neither Ukraine nor NATO can do anything to prevent it from happening.

This is a particularly bitter pill to swallow for Ukraine, since it was once home to the world’s third-largest cache of nuclear weapons. After the collapse of the Soviet Union, Ukraine inherited a significant slice of the Kremlin’s nuclear arsenal. But in 1994, the newly independent country decided to surrender that arsenal in exchange for assurances from Russia, the United Kingdom, and the United States that its sovereignty and territorial integrity would be respected. The agreement, known as the Budapest Memorandum, is one that many Ukrainians have come to regret—first in the wake of Russia’s 2014 annexation of Crimea and invasion of eastern Ukraine, and now even more so after its all-out assault on the country. If Ukraine had held on to its arsenal, many have argued, Putin would never have dared to invade the country.

The hard truth is that the United States now has few good options for containing Iran’s nuclear program. It can persist with the no-deal status quo, allowing Iran to continue inching closer to a bomb while suffering under sanctions. It can pursue a return to the 2015 agreement and then attempt to get Iran to agree to a “longer and stronger” pact, as the Biden team has suggested. It can try for various other deals, either more or less stringent than the 2015 agreement. Or it can attempt to destroy Iran’s nuclear infrastructure with a military strike, possibly setting Tehran’s progress toward a bomb back by a few years but almost certainly provoking retaliation and possibly a sprint toward the nuclear finish line.

Whether they regard it as competitive, cooperative, or confrontational, virtually all observers agree that the U.S.-China relationship is consequential. From cyber norms and AI to military tensions in the Taiwan Strait and the global struggle to turn the tide on climate change, how Washington and Beijing manage their shared future will shape the globe for decades to come. Through research and relationship-building, the Center is dedicated to helping the U.S. and China collaborate and compete without conflict.

The regime built around the 1970 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) has helped curtail the spread of nuclear arms for fifty years. In hindsight, it is remarkable only nine states possess the world’s most powerful weapon. The NPT achieved much success during Cold War bipolarity and U.S. unipolarity in its aftermath. But today, China’s rise and Russia’s resurgence have ushered in a new era of emerging multipolarity. Can the treaty withstand the potential challenges of this dynamic environment? There is a real risk that multipolarity may shake the scaffolding of the nonproliferation regime, presenting a significant test to the NPT’s durability. This article identifies four essential elements of the nonproliferation regime: widespread membership, adaptability, enforcement, and fairness. History suggests bipolarity and unipolarity in the international system largely sustained and promoted these NPT features. When international regimes lack such elements, it sharply curtails their long-term efficacy.

States frequently acquire proof that other states have violated norms. Yet, existing theories do not fully explain how states wield such proof to coerce wrongdoers. Four case studies of nuclear proliferation probe a novel theory of how states coerce norm violators by concealing, sharing privately, or publicizing proof of guilt.