Over the long course of the nuclear age, millions of people—from Hiroshima and Nagasaki to the United States, Russia, and around the globe—have stood up to demand meaningful action to halt arms racing, end nuclear weapons testing, reduce the number and role of nuclear weapons, and move toward the elimination of nuclear weapons. But without renewed public pressure and focused international demands for renewed disarmament diplomacy between Washington and Moscow, a dangerous, unconstrained global nuclear arms race is on the horizon. Already unsteady and dangerous relations between Moscow and Washington would become far worse.

Through the Cold War years, Soviet and American leaders from time to time responded to public calls for action to eliminate the nuclear threat and recognized the value arms control in creating more stable and predictable international relations. In the wake of the 1962 Cuban missile crisis, they began to work together to prevent the spread of nuclear weapons through the 1968 nuclear Non-Proliferation Treaty (NPT) and to slow the arms race through a series of bilateral arms control and arms reduction agreements. These agreements constrained nuclear competition, reduced nuclear stockpiles, and reduced the threat of nuclear war.

But there is no room for complacency. The nuclear weapons threat has not gone away. Nuclear competition is accelerating, and the danger of a conflict between nuclear-armed adversaries is growing.

Today the world’s nine nuclear-armed states possess some 13,000 nuclear weapons, more than 90 percent of which are held by the United States and Russia. Although their stockpiles have decreased significantly from peak Cold War levels, each country still deploys some 1,400 deadly nuclear warheads, on hundreds of long-range, land- and sea-based missiles and bombers, with thousands more warheads in reserve.

If used, these weapons could kill or injure 100 million people in just a few hours, and poison millions more in the following days and weeks. The effects would be catastrophic and unacceptable. Yet the risk of such nuclear war is higher in the wake of Russian President Vladimir Putin’s threats of nuclear use against any state that might try to interfere in Russia’s invasion of Ukraine.

At the same time, key bilateral nuclear arms control agreements designed to reduce tensions and prevent arms racing, such as the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, are either gone or are in jeopardy.

Worsening tensions over Russia’s war in Ukraine are also threatening the last remaining treaty limiting the size and composition of the deadly arsenals—the 2010 New Strategic Arms Reduction Treaty (New START), which limits each side to no more than 1,550 deployed strategic warheads. In February 2021, just days before it was to expire, Presidents Joe Biden and Vladimir Putin agreed to extend the treaty by another five years, and later that year they relaunched a “Strategic Stability Dialogue” with the goal of negotiating further nuclear reductions.

But on August 8, the Russian Foreign Ministry announced that it wouldn’t support the resumption of inspections of its nuclear arsenal under New START (which had been suspended in response to Covid) because travel restrictions imposed by the United States following the invasion of Ukraine make it difficult for Russia to conduct inspections of US nuclear weapons installations. US officials say they wanted to have a team of US inspectors resume on-site monitoring in Russia.

The New START inspections snafu, combined with tensions over Ukraine are also holding up the resumption of US-Russian talks on strategic stability and arms control which have been suspended since Russia launched its invasion. Negotiations on new, follow-on nuclear arms control agreements have been put on indefinite hold.

Without new arrangements to supersede New START, there won’t be any limits on the size or composition of the world’s two largest nuclear arsenals for the first time since 1972. Without commonsense arms control guardrails, the dangers of unconstrained global nuclear arms racing, and nuclear war, will only grow.

Both presidents seem to recognize the danger and say they want to negotiate new arms reduction agreements, but they have not yet agreed to resume their dialogue, and both suggest the resumption of talks depends on the behavior of the other side.

“Our progress must continue beyond the New START extension,” Biden wrote on June 2. “Even as we rally the world to hold Russia accountable for its brutal and unprovoked war on Ukraine, we must continue to engage Russia on issues of strategic stability,” Biden explained in a letter to the Arms Control Association. “Today—perhaps more than any other time since the Cold War—we must work to reduce the risk of an arms race or nuclear escalation.”

But when asked to say when talks might resume, Assistant Secretary of State Mallory Stewart said on June 2, “If there was some way to indicate good faith on their side…we could consider something.”

For his part, Russian President Vladimir Putin said on June 30 that “Russia is open to dialogue on ensuring strategic stability, preserving agreements on the nonproliferation of weapons of mass destruction, and improving the situation in arms control.”

President Biden reiterated the call for renewed nuclear arms control talks in an August 1 statement to a major governmental conference on the future of the nuclear Nonproliferation Treaty being held this month at UN headquarters. “Today, my Administration is ready to expeditiously negotiate a new arms control framework to replace New START when it expires in 2026,” he wrote—adding the caveat: “But negotiation requires a willing partner operating in good faith.”

The snafu over New START inspections, however, is sure to undermine confidence on both sides that the other is serious about making progress.

Given that the war could drag on for many more months, and with time running short on New START, now is the time for each side to test each other’s seriousness by immediately resolving differences blocking the restart of New START inspections and agreeing to begin negotiations, without conditions, on new arms control arrangements to supersede New START.

New understandings need not be put in the form of formal treaties that require approval by the Russian Duma and or the gridlocked US Senate. Binding executive agreements, like the first US-Soviet arms control deal would suffice. But to make lasting progress, they will need to begin talks soon addressing several key issues:

• Limits on strategic arsenals. A key objective of the next round of talks should be deeper, verifiable reductions in the total number of deployed strategic nuclear warheads and delivery systems. In 2013 the Obama administration determined that the United States could further reduce its strategic nuclear forces by up to one-third below New START levels (to 1,000) and still meet core nuclear deterrence goals. New limits will need to factor in new systems being developed by both sides, including hypersonic weapons. At a minimum, US and Russian leaders should issue unilateral reciprocal commitments to respect the central limits of New START until such time as new agreements that supersede New START are concluded.
• Tactical nuclear weapons. The United States wants to discuss measures to address Russia’s larger stockpile of nonstrategic nuclear weapons. One option would be to agree to exchange detailed declarations on tactical nuclear stockpiles, including warheads in storage. Making progress on tactical nuclear arms control, however, should not become a prerequisite for lower ceilings on strategic nuclear arsenals.
• Understandings on strategic interceptors. US efforts to further limit Russian nuclear weapons and bring China into the arms control process are unlikely to gain traction unless Washington agrees to seriously discuss constraints on its long-range missile defense capabilities. Fielding a sufficient number of US missile interceptors to mitigate the threat of a limited ballistic attack from North Korea or Iran and agreeing to binding limits on the quantity, location, and capability of missile defense systems should not be mutually exclusive.
• Averting an intermediate-range missile race. With the recent collapse of the Intermediate-range Nuclear Forces Treaty (INF) Treaty, the risk of a new missile race is Europe will grow. Biden, in coordination with NATO, should counter Russia’s 2020 proposal for a verifiable moratorium on the deployment in Europe of missiles formerly banned by the INF Treaty. Although imperfect, the Russian proposal is a starting point. Another option would be to verifiably ban nuclear-armed ground- and sea-launched cruise and ballistic missiles.
• Engaging the other NPT nuclear-armed states. According to US projections, China could increase the size of its arsenal, which now estimated to consist of nearly 300 nuclear weapons. These moves, while concerning, do not justify alarmism. It is likely Beijing wants to make its nuclear retaliatory force less vulnerable to potential US attack. But in order to reduce current and future risks, new and creative efforts will be necessary to get China off the nuclear disarmament sidelines, and US leaders must not only press their Chinese counterparts to exercise restraint but also show they are willing to address Beijing’s concerns.

Sustaining progress on nuclear disarmament, particularly between the United States and Russia, is necessary to avert unconstrained nuclear arms racing and nuclear conflict, and to move us closer to a world without nuclear weapons. As then-Senator Joe Biden told an Arms Control Association meeting in 1979, “Pursuing arms control is not a luxury or a sign of weakness, but an international responsibility and a national necessity.” That was true during the Cold War, and it is true today.