Dmitri Medvedev, former President and Prime Minister of the Russian Federation, took to social media on February 25, 2022 to post a chilling message: Russia may be ready to give up the New START Treaty, and it may be ready to cut diplomatic ties with the United States and other Western countries. As Medvedev said, “As for diplomatic relations, well, there is no great need for them… It’s time to hang huge padlocks on the embassies. We can continue our contacts looking at each other through binoculars and gun sights.”

Medvedev certainly did not post without checking whether the message would be welcome. His words, therefore, presage the possibility that Russia will cut itself off from everything that it has accomplished to control and limit nuclear weapons. Since the Cuban Missile Crisis, sixty years ago this year, the USSR and then the Russian Federation have played a proud and generally positive role in preventing nuclear proliferation, halting nuclear testing, and reducing nuclear stockpiles. Even as Russian tanks rolled into Ukraine, experienced Russian negotiators in Vienna were working with the United States and other partners to resuscitate the Iran nuclear deal. Another irony of this blazing crisis.

It is not too much to say that Russia has been a giant of the nonproliferation regime. The major treaties of the twentieth century have all benefitted from the skills of Russian negotiators and the intellect of Russian experts. The Non-Proliferation Treaty itself was the product of problem-solving ideas from senior Soviet and American diplomats, Ambassadors Roland Timerbaev and George Bunn, at a time when the United States and USSR were otherwise facing off over the Middle East and Vietnam. Tensions were so high that in 1967, the U.S. nuclear alert level was raised during a solar storm. Somehow, no matter how bad the crisis, the two countries continued talking to get nuclear weapons under control and prevent their spread.

Now, on the back of the invasion of Ukraine, this proud tradition is breaking asunder. What can we expect? The main options seem to be two: First, Russia isolates itself, becoming a pariah state unwilling to play any responsible international role. This seems to be the message of Medvedev’s threat to leave the New START Treaty and shutter the embassies in Moscow. Alternatively, Moscow picks some arenas where it wants to continue to pursue its objectives with mutual benefits to its partners at the negotiating table, for the sake of global stability and its own security.

Let’s consider the options as they relate to nuclear diplomacy. If Russia isolates itself, then further progress on nuclear non-proliferation becomes difficult. The Non-Proliferation Treaty Review conference, repeatedly postponed due to the COVID pandemic, is now scheduled to take place in August 2022. Normally, Russia would join the four other nuclear weapons states—US, UK, France and China—to defend its record and bolster continuing progress on the disarmament pillar of the treaty. Just in January 2022, the P 5 nuclear weapons states joined in reiterating the statement of Presidents Reagan and Gorbachev that nuclear war cannot be won and must never be fought. This was meant to be the centerpiece of a positive P 5 disarmament agenda at the review conference, which would also extend to bolstering action on nuclear nonproliferation and supporting peaceful uses of the atom. We will have to see if the P 5 can hold together to pursue these goals.

China’s role will be an interesting one, and vital. China has hidden behind Russia and the United States for many years, arguing that the much larger U.S. and Russian strategic nuclear arsenals handed Washington and Moscow the leadership of the nuclear nonproliferation and disarmament regimes. Now China’s own strategic arsenal is growing and it seems inclined, at least in the context of the NPT nuclear weapon states, to play a leadership role.

If Russia absents itself from nuclear diplomacy, will China be willing to step up to help lead? And will the United States be willing to admit it to leadership, given the animus between Washington and Beijing? The two capitals should be pondering these questions now, while we watch the disaster unfold in Ukraine. Of course, it is still a fact that the U.S. and Russian nuclear arsenals are a lot larger than China’s, and China’s ongoing modernization will not change that fact any time soon.

Therefore, the primary purpose of cooperation between the United States and China in the immediate period should be to work together closely to shore up the Non-Proliferation Treaty regime and ensure a successful review conference. They should also work to preserve other existing mechanisms such as the Organization for the Prohibition of Chemical Weapons (OPCW) and the Comprehensive Test Ban Treaty Organization (CTBTO). Otherwise, Russia may begin to play a wrecking role.

The United States and China might also consider working to constrain weapon systems where they have some equality of capability, such as INF missiles or direct ascent anti-satellite weapons (ASAT). U.S. Vice President Kamala Harris announced a unilateral U.S. ban on testing destructive ASAT systems in April 2022 and invited other countries to join. China may wish to take up that offer, in order to convey a responsible attitude toward sustaining space operations. If China and the United States can show early ability to work together and produce results, then the world will breathe a collective sigh of relief that we are not heading into a free-for-all involving weapons of mass destruction and other critical systems.

However, I have to say that with Vladimir Putin threatening nuclear use in the Ukraine crisis, a productive NPT review conference in August seems a faint hope. If Putin decides to proceed to nuclear use, then we are entering territory untrodden since Hiroshima and Nagasaki, over seventy- five years ago.

If this happens, then the global community would react with horror. It would doubtless scramble to minimize the damage, succor the victims, and up the deterrence ante to prevent escalation. The moral burden of using nuclear weapons in wartime would land squarely on Russia, shifting from where it has rested since 1945, on the United States.

If stability is somehow restored, the question will then come: what next? Is it even worth trying again to ensure nuclear peace at the negotiating table?

In the first place, I believe that we will have to work hard to preserve the Nonproliferation Treaty regime, because the horizontal proliferation pressures emanating from the crisis will be strong. Again, the P 5 should try to hold together to preserve the NPT, with China perhaps taking a more prominent role than it has in the past.

If Russia refuses to play, then it will be setting itself up as a very large nuclear pariah state.

Let us hope for the other option, i.e., that Russia draws back from the nuclear brink and wants to return to the negotiating table, working with the P 5 to preserve the nonproliferation regime. In this situation, other countries, the United States included, will have to consider whether the benefits are worth the costs of dealing with Moscow.

Let me address this question as follows: Where nuclear weapons are concerned, the U.S. and its allies have tried for real progress at the negotiating table since the Cuban Missile Crisis in 1962. That crisis brought home the alternative—the existential threat that nuclear weapons pose. A Russian nuclear use in 2022, sixty years later, would renew that urgency and presumably, the necessity of negotiating with Russia. It would be an existential necessity, not a reward to Russia for its bad behavior.

Looming over all these considerations is Vladimir Putin and his role as chief Russian decision-maker in the continuing crisis. The President of the United States has called him a war criminal, and the Kremlin has shot back that such language is unwarranted and unforgivable. Although war crimes are a matter for the international courts to decide, the civilian deaths in Ukraine—at Bucha, Mariupol and other sites—are accumulating much evidence.

In these circumstances, the return of Russia to any negotiating table will be hard, never mind a bilateral nuclear one with the United States. First and foremost, the two Presidents will have to be willing to resume nuclear talks, even if they are not willing to engage each other directly. They will have to issue instructions to their negotiators.

Then, confidence will have to be renewed between the negotiators themselves. The negotiators know each other and have been working steadily together, for example, on renewing the Iran nuclear deal, so perhaps renewing confidence will not be insurmountable.

In my view, and I stress I am speaking only for myself: before nuclear talks resume, first, a stable ceasefire must be in place in Ukraine; second, the withdrawal of Russian troops behind a ceasefire line agreed with the Ukrainians must be complete; and third, the reconstruction of Ukraine must be underway. In other words, a peace process must be well in train before we return to nuclear stability talks with Russia.

A Russian nuclear use in the Ukraine crisis would heighten these dynamics and cause the United States to think long and hard about what it can achieve at the negotiating table. In my view, as always, the U.S. national security interest must be paramount. If nuclear negotiations serve it in countering this existential threat and preventing a nuclear arms race, then the United States should be ready to talk.

In the end, the crisis in Ukraine may be the sharp shock that boots us into redoubling our efforts to constrain nuclear weapons. If we do not seize the chance, then we may be heading back to Cold War nuclear arms racing. Vladimir Putin has been threatening a crisis worse than the Cuban Missile Crisis. He meant it.