With Russia’s war against Ukraine in its second year and tensions growing in the U.S.-Chinese relationship, nuclear weapons are back on the global political agenda. At a summit in Hiroshima on May 19, G-7 leaders committed to promoting “responsible nuclear behavior,” including risk reduction measures and greater transparency about states’ nuclear arsenals. Despite this renewed attention to the danger of nuclear weapons, traditional arms control—in which nuclear powers formally agree to take steps to reduce their arsenals—has broken down altogether.

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.

Russia’s invasion of Ukraine is upending one long-standing geopolitical norm after the other, with nuclear arms control potentially one of the next to go. In 2021, the United States and Russia extended the 2010 New START pact—the only remaining major nuclear agreement between the two countries—through 2026. Russia is now threatening to halt U.S. military inspections required under the agreement, but there are challenges for the future of arms control that go beyond the fate of New START.

There are two possible pathways for arms control after Russia’s war in Ukraine. The first, less likely scenario is an arms control renaissance. The 1962 Cuban missile crisis, for example, was a wake-up call for the United States and Soviet Union to the dangers of nuclear escalation. The decade after the crisis saw a suite of arms control efforts, including the Limited Test Ban Treaty, the Nuclear Non-Proliferation Treaty (NPT), the Strategic Arms Limitation Talks, the Anti-Ballistic Missile Treaty, and a series of risk-reduction measures, such as the Incidents at Sea Agreement. The Ukraine crisis may prove another impetus for post-conflict cooperation, albeit a costly one.

Heather Williams, a nuclear expert at King’s College London and visiting fellow at the Harvard Kennedy School, said it was “totally ambiguous” but in keeping with a leader who has a history of being a “nuclear bully”. “It is classic Putin, creating ambiguity and uncertainty,” Williams said. “Putin is so good at that because he knows that it keeps people on edge.”

Until now, nuclear weapons have largely been in the background of the Ukraine conflict. That changed when Russian President Vladimir Putin elevated Russia’s military status to ‘special service regime’, including its nuclear forces. In practice, this ‘special status’ could mean higher readiness and survivability of the Russian nuclear command authority along with its nuclear forces.

Putin is a nuclear bully. He has much more at stake in Ukraine than NATO does and is willing to escalate the crisis to get his way. None of this is new. What this announcement signals, however, is two things: resistance to the Russian invasion is hurting, and Putin is getting desperate. While the first point should inspire hope for Ukraine and Europe, the second necessitates caution because options for a face-saving resolution to the crisis, without resorting to massive casualties, are dwindling for Putin. But there are still a few off-ramps left, and NATO can also play a role in reducing risks of further escalation.

Michael Krepon’s book Winning and Losing the Nuclear Peace: The Rise, Demise, and Revival of Arms Control comes at the perfect time. On the one hand, 2021 was a relative boon for arms control compared to the past five years. In January, U.S. President Joe Biden and Russian President Vladimir Putin agreed to extend the 2010 New Strategic Arms Reduction Treaty (New START) for five years. Following a summit in June, they also committed to hold strategic stability dialogues to “lay the groundwork for future arms control and risk reduction measures.” On the other hand, the past 20 years have seen a steady erosion of arms control agreements due to Russian violations and U.S. withdrawals. This trajectory raises questions about how this era should be viewed in the context of arms control history and how arms control could contribute to future security. Enter Krepon, who provides both a comprehensive historical narrative and a call to action.