War and Arms Control: When to Pursue Cooperation

Abstract Russian President Vladimir Putin has repeated nuclear threats in connection with the war in Ukraine since Russia invaded on 24 February 2022, and senior Russian military leaders have reportedly considered when and how Moscow might use a tactical nuclear weapon in Ukraine. On 27 October, in this context of rising nuclear risks, the US Department of Defense released its Nuclear Posture Review. It describes the present moment as a time to prepare rather than negotiate. Although now is not the time to begin negotiations towards a formal arms-control treaty, the end of the war in Ukraine will be an important opportunity for pursuing post-crisis arms-control efforts. Meanwhile, during this arms-control interlude, the United States and its allies should lay the groundwork for future arms-control efforts.