As diplomats, activists, and researchers converged on Vienna in June for the first meeting of states-parties to the Treaty on the Prohibition of Nuclear Weapons (TPNW), recent tragic world events highlighted how critical it was to convene this multilateral forum on nuclear disarmament.

Since February, Russia’s war against Ukraine has epitomized the grave dangers of a world where nine states possess approximately 12,700 nuclear weapons.¹ That Russia could invade a sovereign state and indiscriminately target its civilian population, while using nuclear threats to deter NATO from intervening, has stunned the world. It offers a stark reminder that possessing nuclear arms can enable abhorrent violations of international law

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.

The Biden administration not only inherits a country where COVID-19 is surging and jobs are hemorrhaging, but he also takes over a perilous global landscape when it comes to nuclear arms control and disarmament. The Trump years saw the dissolution of the Intermediate-Range Nuclear Forces Treaty, and US withdrawal from the Joint Comprehensive Plan of Action (i.e. the Iran nuclear deal) and the Open Skies Treaty. President Trump has not extended New START, the last remaining arms control treaty, leaving 16 days for the new administration to work out an extension before the treaty expires.

The Treaty on the Prohibition of Nuclear Weapons (TPNW) poses a challenge to decades of Japanese nuclear policy. While Japan has relied on the US nuclear umbrella since the aftermath of World War II, numerous pro-disarmament groups — including the Hibakusha — are calling for Tokyo to join the Treaty. The authors contribute to these discussions with commentary on a new national survey they conducted in Japan (N = 1,333). Their results indicate that baseline support for the Prime Minister signing and the Diet ratifying the TPNW stands at approximately 75% of the Japanese public.

Universal norms have power—US leaders know this. For proponents of nuclear deterrence like the US government, the norms of the NPT are strategically valuable because they allow the United States and four other states to maintain their nuclear weapons while keeping the rest of the world from possessing their own. In contrast, the norm promoted by the ban treaty is meant to apply to all states and so US leaders fear its long-term effects.

On August 6, 1945, the United States dropped an atomic bomb on Hiroshima, Japan, launching the nuclear age. On the 75th anniversary of that somber event, Belfer Center experts reflect on the event and its aftermath. 

Rebecca Davis Gibbons writes that having a full appreciation of the consequences of nuclear weapons and their place in society means learning from the stories of the survivors of Hiroshima and Nagasaki—but also from the stories from other survivors of nuclear explosions: those who lived and worked adjacent to testing sites in Algeria, French Polynesia, Australia, the United States, France, the Republic of the Marshall Islands, Western China, and Kazakhstan.

Rebecca Davis Gibbons and Stephen Herzog provide an update on current efforts to eliminate nuclear weapons. 

Recent scholarship on nuclear proliferation finds that many forms of nuclear assistance increase the odds that recipient states pursue nuclear weapons programs. While these studies may help us understand select cases of proliferation, they overshadow the role of nuclear supply in bolstering global nonproliferation efforts. After the risks of nuclear assistance became well-known following India’s nuclear explosion in 1974, most major suppliers conditioned their assistance on recipients joining nonproliferation agreements. Case studies of states’ decision-making regarding these agreements illustrate how the provision of nuclear technology has been an effective tool in persuading states to join such agreements, the most important of which is the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). By joining the NPT, states strengthen the global nonproliferation regime and increase the costs of any potential future decision to proliferate. The offer of nuclear assistance has done far more to bolster global nuclear nonproliferation efforts than recent research suggests.