Editor's note:

The U.S.-Russia nuclear arms control regime is in danger—and neither Vladimir Putin nor Donald Trump appear committed to saving it. Yet given enough political will, a solution could be found readily, writes Steven Pifer. This post originally appeared in the Berlin Policy Journal.

Nuclear arms control has been a central feature of the relationship between Washington and Moscow for some 50 years, but the nuclear arms control regime appears increasingly fragile. Several factors are placing the regime under stress, and there are currently no discussions underway that might bolster it. U.S.-Russian relations have fallen to their lowest point since the end of the Cold War, beset by problems including Russia’s aggression against Ukraine, differences over Syria, and Moscow’s interference in the U.S. presidential election. Should the nuclear arms control regime unravel—a prospect that is unfortunately very real—the world would become a more uncertain and dangerous place.

U.S. and Soviet officials began nuclear arms control negotiations in the late 1960s. Over the next four decades, they produced agreements like the Strategic Arms Limitations Talks (SALT), the Intermediate-range Nuclear Forces Treaty (INF), and the Strategic Arms Reduction Treaty (START). Thanks to those agreements and other unilateral decisions, the United States and Russia currently maintain nuclear arsenals that are large but only a fraction of their respective Cold War sizes.

The latest agreement, New START, requires the United States and Russia to each reduce to no more than 1,550 deployed strategic warheads on no more than 700 deployed strategic missiles and bombers. Those limits go into full effect in February 2018, and both countries appear on track to meet the limits. Following the conclusion of New START, then-President Barack Obama proposed a new round of arms reduction negotiations that would include non-strategic nuclear weapons and non-deployed strategic weapons—meaning that for the first time, Washington and Moscow would negotiate on all nuclear weapons in their arsenals. Russian officials balked, citing concerns such as missile defense and conventional strike systems. They also called for the next negotiation to be multilateral, although the United States and Russia each maintain a nuclear arsenal that is more than 10 times the size of that of any third country.

Over the remainder of the Obama administration, the two countries were unable to find a formula that would allow new negotiations. U.S. and Russian officials have conducted one round of strategic stability talks since President Donald Trump took office, but those appear to have produced little more than agreement that there would be a second round.

The eroding INF Treaty

The fate of the INF Treaty poses the most pressing challenge to the nuclear arms control regime. Signed by Ronald Reagan and Mikhail Gorbachev in December 1987, the treaty banned all U.S. and Soviet ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers. By mid-1991, the two countries had destroyed some 2,700 missiles.

In 2014, the Obama administration charged that Russia had violated the treaty by testing a prohibited ground-launched cruise missile of intermediate range. Then, in 2017, U.S. officials said that Russia had begun deploying the missile, which bears the Russian designator 9M729 and which the United States calls the SSC-8. Russian officials deny that they have violated the treaty, and instead charge the United States with three violations. Two are without merit, but Moscow’s claim that the launcher system for “Aegis Ashore,” the SM-3 missile interceptor site in Romania (and soon Poland as well), represents a violation appears to have some substance. Ashore’s vertical launch system, when on U.S. Navy warships, can launch cruise missiles and other weapons as well as the SM-3, and the Russians say Aegis Ashore could hold ground-launched cruise missiles banned by the INF Treaty.

With more political will in Moscow and Washington, these problems could be addressed. The Russians, however, have thus far refused to even acknowledge any question about their compliance. For their part, Obama administration officials privately said that they would be willing to address Russian concerns if Moscow took the U.S. charge regarding the Russian ground-launched cruise missile seriously.

Silent allies

Since taking office, the Trump administration has conducted a review of the situation, while Republicans in Congress have added language to the National Defense Authorization Act that would authorize the Pentagon to develop a U.S. ground-launched cruise missile. U.S. officials have also consulted with NATO allies on the Russian violation.

On December 8, 2017—the 30th anniversary of the signing of the INF Treaty—the Trump administration announced that it remained committed to the treaty and would pursue an integrated strategy to bring Russia back into compliance. Under this strategy, the United States will (1) continue its pursuit of a diplomatic settlement, including through the Special Consultative Commission established by the treaty to discuss, among other things, compliance issues; (2) commence research and development of options for US intermediate-range ground-launched missiles (which would not per se violate the INF Treaty, though any flight test would); and (3) apply economic sanctions on Russian entities that developed and produced the SSC-8.

Meanwhile, U.S. allies in Europe and Asia have said virtually nothing in public about the Russian violation, a missile designed to strike targets in their neighborhood rather than in the United States. This silence sends the wrong message to Moscow: for the Kremlin, this violation is just one part of an already troubled relationship with Washington, rather than a major political problem with the country’s neighbors. Moreover, if leaders in Berlin, Rome, The Hague, Brussels, and Tokyo, among other capitals, do not vigorously protest the Russian violation, their desire to maintain the treaty may not carry much weight with the Trump administration.

Trump and New START

If the INF Treaty collapses, it would increase the pressure on New START. New START expires by design in 2021, though it can be extended by up to five years. One would expect some quarters in Washington to oppose extending New START if the INF Treaty breaks down or Russia remains in violation; indeed, some Republicans on Capitol Hill have already sought to block funds for New START’s extension if Russia does not comply with the INF Treaty. Administration officials say that the question of extending New START will be considered after they see what happens in February 2018 and have a chance to complete a nuclear posture review.

U.S. military leaders would most likely favor extension. They have testified to Congress that New START is in the American interest, emphasizing in particular the transparency regarding Russian strategic forces that is provided by the treaty’s data exchanges, notifications, and inspections.

Whether President Trump shares that view is an open question, in part because he seems to have a limited understanding of strategic nuclear issues. When President Vladimir Putin raised the possible extension of New START in an early 2017 phone conversation, President Trump was reportedly unclear what New START was, but denounced it as a bad Obama deal.

A world without arms control limits

On its current course, it is difficult to see the INF Treaty surviving much longer. While the U.S. administration remains nominally committed to the treaty, pressure will grow to withdraw if the Russian violation is not addressed. (That said, it had better be able to present compelling evidence of a Russian violation, or the United States will get blamed for the treaty’s demise.) If the INF Treaty is terminated or doubts about Russian compliance remain unresolved, it would make extension of New START beyond 2021 less likely.

Thus 2021 could see the end of negotiated limits on US and Russian nuclear forces, at a time when Russia is completing its nuclear modernization program and the United States is beginning to accelerate its planned modernization of its strategic delivery systems. Without these limits, the Russian military can be expected to openly deploy its intermediate-range ground-launched cruise missile. Might Moscow also decide to complement these by developing and deploying an intermediate-range ballistic missile?

Given budget limitations, it could be that neither Russia nor the United States would dramatically expand its strategic nuclear force numbers beyond the levels permitted by New START. Neither side, however, would be constrained by treaty limits. The Russian military hopes to field a large intercontinental ballistic missile (ICBM) called the Sarmat. New START would likely require that that missile be deployed with fewer warheads than it is capable of carrying—but would the Russian military forgo deploying the maximum number of warheads absent New START? On the American side, the U.S. Navy deploys an average of four to five warheads on its Trident II submarine-launched ballistic missiles (SLBMs), which can carry eight warheads apiece. Absent New START, would the Pentagon be tempted to deploy a larger number of warheads on its SLBMs?

The danger of proliferation

Both sides would also lose the information provided by New START. Under the treaty, the sides exchange detailed data on their strategic forces every six months, and an average of 2,000 notifications every year regarding changes to their strategic forces. The treaty also allows each side to conduct up to 18 inspections per year of the other side’s deployed and non-deployed strategic forces. These provisions yield a huge amount of information, including the numbers of warheads on individual ICBMs and SLBMs at bases or submarine ports that are inspected. It would be difficult and expensive to develop other means of acquiring such information; without it, both sides would face greater uncertainty and be more likely to make worst-case assumptions about the size and composition of the other’s strategic forces. That would inevitably mean more costly decisions about how each side would equip and operate its own strategic forces.

Potential third country reactions also merit consideration. If the United States and Russia abandon nuclear arms limits, what would that mean for the nuclear non-proliferation regime and efforts to prevent the emergence of new nuclear weapons states? If the two nuclear superpowers do not limit their arsenals, can they credibly ask other countries not to acquire nuclear weapons?

China has built up its nuclear forces at a modest pace, in part because Beijing has operated in a context in which there were limits on U.S. and Russian nuclear forces. The country certainly has the economic capacity to expand its nuclear forces at a much more rapid rate. Without any international limits, would it be tempted to do so in an attempt to narrow the gap between its nuclear forces and those of the United States and Russia?

Maintaining the regime

Washington and Moscow can still avoid the breakdown of the nuclear arms control regime. They could have a forthright dialogue on how to preserve the INF Treaty, using the Special Verification Commission to work out ways to address compliance concerns.

For example, the sides could agree that Russia would exhibit its SSC-8 ground-launched cruise missile and provide a briefing on its characteristics to U.S. experts. With more information, those experts might conclude that the missile does not violate the treaty. Of course, if it really has a range between 500 and 5,500 kilometers, the missiles would have to be eliminated.
Meanwhile, the U.S. side could address Russian concerns on Aegis Ashore by introducing observable differences—functionally-related observable differences, if possible—to distinguish those SM-3 interceptor launchers from launchers on U.S. warships. The sides might also set procedures under which Russian inspectors could periodically visit the SM-3 interceptor sites in Romania and Poland to confirm that the launch systems contained SM-3 interceptors, not cruise missiles.

Washington and Moscow could also agree to extend New START until 2026. That would preserve the treaty’s benefits and allow time for negotiation of a possible follow-on agreement. Of course, resolution of compliance concerns regarding the INF Treaty would create a much more positive atmosphere for consideration of New START’s extension.

Unilateral commitments

Furthermore, U.S. and Russian officials could use the strategic stability talks to explore the possibility of new negotiations on reducing nuclear arms, ideally including non-strategic nuclear weapons and non-deployed strategic warheads. To get to that point, Washington would almost certainly have to agree to some discussion of missile defense. It is difficult to see the Senate consenting to ratification of a treaty that limits missile defense, but a number of steps short of a treaty—an executive agreement on missile defense transparency, a NATO announcement of a self-imposed limit on the number of SM-3 interceptors in Europe, and/or a NATO decision to complete the SM-3 site in Poland but not deploy interceptors there—might interest Moscow.

As for third-country nuclear forces, the disparity in numbers between U.S. and Russian nuclear weapons levels and the nuclear weapons levels of third countries makes it hard to conceive of a workable multilateral agreement, particularly if third countries insisted on equal limits. However, in the context of a U.S.-Russian agreement that further reduced their nuclear arms levels below New START limits, it might be possible to get third countries, or at least Britain, France, and China, to commit unilaterally to not increase their total numbers of nuclear weapons.

An end to the nuclear arms control regime would be fraught with negative consequences for the United States, Russia, and the world, and the U.S. and Russia should carefully consider how they proceed regarding the INF and New START treaties. With political will, the nuclear arms control regime can be maintained and perhaps strengthened, but doing so will require wise decisions in Washington and Moscow—ideally with appropriate encouragement from U.S. allies and others in Europe and Asia, who will see their security diminished if the INF and New START treaties lapse.