Nuclear Issues

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.

Mariana Budjeryn's Inheriting the Bomb tells the story of how Ukraine came into possession of the world's third-largest nuclear arsenal—larger than the combined stockpiles of China, France, and the United Kingdom at the time—and decided to disarm peacefully a few years later. Ukraine's denuclearization was far from a straightforward process. After initially renouncing nuclear weapons, Ukrainian officials sought recognition that their newly independent country was a rightful heir to part of the Soviet cache, deserving of equal treatment, financial compensation, and pledges that disarmament would not endanger Ukraine's security. 

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.

David M. Allison argues that in ascending order of predictive power, warnings of an imminent nuclear strike would come from Russian whistleblowers, the U.S. intelligence community, and Putin himself.

In late October, after eight months of war, the Russian government claimed that Ukraine was preparing to use a "dirty bomb" and blame it on Russia. There was never any evidence for this claim. But Russia's ambassador to the UN, Vassily Nbenzia, nevertheless sent a letter (reproduced below) demanding that the Security Council hold a meeting to discuss the "dirty bomb" issue.

Russia's claims have been widely dismissed. Nevertheless, Russian spokesmen are continuing to press the narrative.  (See, for example, the November 8 statement from Anatoliy Antonov, Russia's ambassador to the United States, which slurs together with the dirty bomb theme a variety of other false claims about Ukraine.) It seems worthwhile, therefore, to debunk Russia's claims in detail.

Abolghasem Bayyenat argues that without the JCPOA restrictions in place, Iran's nuclear program will expand and continue to acquire irreversible technical knowledge and competencies.

For months, evidence has accumulated that North Korea may be preparing its seventh nuclear explosive test. Continuous warnings by analysts and the media about this possibility are a sobering reminder that Pyongyang's continued pursuit of a larger nuclear arsenal remains a challenge for the Non-Proliferation Treaty and the nonproliferation regime. This continues to be the case even as the public and leaders around the world have largely shifted their attention to the nuclear dimensions of the war in Ukraine.

From June 21-23, dozens of countries gathered in Vienna to discuss how to implement the new UN Treaty on the Prohibition of Nuclear Weapons (TPNW)External link. They were joined by nuclear disarmament activists from around the world, including hibakusha – atomic bombing survivors from Hiroshima and Nagasaki. Swiss diplomats were also present, but only to observe rather than directly participate. This may seem surprising, but it’s consistent with Switzerland’s pragmatism on questions of nuclear abolition.

Switzerland’s decision was based on careful study. Following a report by an interdepartmental working groupExternal link, the government opted not to become a TPNW member in 2018 and 2019. Instead, the country wants to work on nuclear disarmament with states inside and outside the treaty. Practically speaking, this means sending Swiss experts to observe TPNW proceedings. And that engagement is a good thing because the nuclear ban treaty is here to stay and cannot be ignored.

Existing risk reduction tools are designed to prevent risks associated with misperception or inadvertent escalation. They are not tailored to the type of intentional escalation and risk-taking that Russian President Vladimir Putin has demonstrated with regards to Ukraine. Preventing further escalation and nuclear use will require strengthening deterrence and developing new risk reduction tools.

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.