Kari A. Bingen and Heather W. Williams write that if Russia plans to deploy nuclear weapons in space to target satellites, the threat is definitely serious—and the U.S. should act fast.

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.