Just days into Russia’s invasion of Ukraine, Dmitri Medvedev, the former president and prime minister of Russia, took to social media to post a chilling message. He raged against Western sanctions on his country and suggested darkly that Russia could rip up some of its most important agreements with the West. He mentioned the New START treaty, the nuclear arms reduction agreement signed with the United States over a decade ago, but the threat was broader still: the sundering of all diplomatic ties with Western countries. “It’s time to hang huge padlocks on the embassies,” he wrote.
Now that Russian President Vladimir Putin has taken steps to mobilize his nuclear forces—and made more likely the once remote possibility that nuclear weapons might be used in modern conflict—Medvedev’s post presages a dangerous turn. Furious at the response to its war in Ukraine, Russia might cut itself off from everything that it has accomplished in controlling and limiting nuclear weapons. Since the Cuban Missile Crisis in 1962, the Soviet Union and then Russia have played a generally positive role in preventing nuclear proliferation, halting nuclear testing, and reducing nuclear stockpiles. Even as Russian tanks have been rolling through Ukraine, experienced Russian negotiators in Vienna have been working with the United States and other partners to resuscitate the Iran nuclear deal.
