Nuclear Issues

David Kearn argues that the idea that the first use of nuclear weapons since 1945 would be by the United States in the defense of Taiwan against a conventional Chinese invasion would have significant, negative, and long-lasting, diplomatic ramifications. It is difficult to fathom the myriad potential consequences, but U.S. nuclear weapon use would almost certainly shatter the non-proliferation regime as a functioning entity, incentivize states (including China) to acquire or improve their existing nuclear arsenal, and damage America's standing globally.

David Kearn argues that even in the absence of restrictive resource and budgetary constraints, a focus on identifying and achieving concrete objectives that will position the United States and its allies to effectively deter aggression in critical regional flashpoints should be the priority given the stressed nature of the defense industrial base and the nuclear enterprise.

David W. Kearn argues that deployment of nuclear weapons cannot rectify a perceived imbalance in conventional forces in the western Pacific.

Herzog, Baron, and Gibbons (HBG) thank Haley Daarstad, RyuGyung Park, and Timea Balogh for replicating their 2022 short article in The Journal of Politics. In that article, HBG tested the malleability of U.S. public support for nuclear disarmament, specifically in the context of the 2017 Treaty on the Prohibition of Nuclear Weapons (TPNW). Their survey experiment reveals that––despite majority public support for eliminating nuclear weapons––Americans’ backing of the TPNW can be significantly attenuated by exposure to elite and group cues opposing the treaty. The resultant article has received considerable attention from policymakers and anti-nuclear activists alike. Daarstad, Park, and Balogh (DPB) offer three main substantive points of comment on HGB's article. First, DPB indicate that the results successfully replicate and note that they “do not find any coding errors that undermine the authors’ analysis or conclusions.” Second, DPB show that the findings also replicate when partisan leaners are coded as political Independents. Finally, and most interestingly, DPB conduct gender-based subgroup analysis and show that there are heterogenous treatment effects among male and female respondents in our sample. HBG address each of these points in turn.

This year's G7 summit in Hiroshima sees nuclear disarmament and non-proliferation sitting high on the agenda, amid rising tensions between the nuclear states and an increasingly divided international order.  Six contributors offer their analyses, including the Belfer Center's Mayumi Fukushima.

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.

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.

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.

What types of foreign policy cues are most likely to turn public opinion against a popular emerging norm? Since 2017, the U.S. government has sought to discredit the Treaty on the Prohibition of Nuclear Weapons and its nuclear nonpossession norm among the largely prodisarmament American public. The authors fielded a national U.S. survey experiment (N=1,219) to evaluate the effects of these elite cues as well as social group cues on public opinion. Their study thus offers one of the first experimental assessments of public attitudes toward nuclear disarmament.