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Q&A

What Happens If the Last Nuclear Arms Control Treaty Expires?

New START is the last nuclear arms control pact left between the United States and Russia. If it isn’t extended, there will be no limits on either countries’ nuclear arsenals for the first time in decades.

Published on September 5, 2019

What is New START?

The New Strategic Arms Reduction Treaty (New START) is an agreement between the United States and Russia that limits certain nuclear weapons. It caps each country at the lowest levels of deployed long-range nuclear forces since early in the Cold War. These are nuclear weapons ready to be used on delivery systems (missiles and bombers) that can reach targets a continent away.

Confused about New START and the INF Treaty? Explore the key differences below.

Why did both countries sign up?

The treaty entered into force in 2011. The then president Barack Obama’s administration successfully negotiated it as a follow-on to the original START Treaty, which was in effect from 1994 to 2009. The older START Treaty had expired without a replacement.

Neither Russia nor the United States were carrying out START-related inspections and notifications during this gap between the agreements, so each country lost valuable insight into the other’s nuclear forces.

Moscow and Washington both wanted provisions that allowed them to be flexible in the make-up of their nuclear arsenals, to inspect each other’s nuclear bases, and to limit either side’s ability to cheat and build a secret force of weapons to break out from the treaty. These provisions provided transparency into each side’s nuclear operations and thereby reduced at least one major source of potential instability between them. The treaty also gives both countries a useful amount of flexibility to decide what mix of missiles or bombers they prefer, as long as the total numbers of these systems remain under the limits.

Why is New START in danger of expiring?

The treaty is set to expire on February 5, 2021. The two countries could extend it by simple agreement. However, U.S. President Donald Trump has expressed hostility toward all agreements negotiated by the Obama administration, including New START. Trump administration officials have refused to commit to extending the treaty, saying they are still evaluating it. In June 2019, National Security Adviser John Bolton said although the administration had not yet reached a decision, New START extension was “unlikely.”

Yet U.S. military leaders have expressed clear support for New START. For example, General John Hyten, the leader of U.S. Strategic Command, has praised New START’s onsite inspections: “We have very good intelligence capabilities, but there’s really nothing that can replace the eyes on, hands-on ability to look at something.” Meanwhile, Russian President Vladimir Putin has said that if Washington shows no interest in extending New START, “we won’t do it, then.”

It would be easy to extend New START. The treaty’s term can be lengthened for up to five additional years—until February 5, 2026—if the two countries’ presidents just agree to do so. Importantly, extension would not need to be ratified by the U.S. Senate. The Senate ratification requirement in the past has posed a major barrier to arms control treaties and would be difficult and time-consuming.

Are there valid reasons for letting New START expire?

Critics say that New START does not limit Russia’s large arsenal of shorter-range nuclear weapons and that Moscow is developing new experimental long-range systems, like its nuclear-powered cruise missile. This criticism is misleading in vital ways. The treaty was never designed to address Russia’s shorter-range arsenal. The long-range missiles it does limit are the only ones that could actually reach the U.S. homeland and therefore pose the greatest threat to U.S. national security.

Moreover, New START would restrict many of Russia’s newer weapons systems. And other new systems would not even be deployed until after the proposed period of treaty extension ends in 2026, meaning that a new agreement would need to be negotiated to deal with these weapons in any case. Letting New START expire is a surefire way to leave Russia’s most threatening long-range nuclear weapons unconstrained, while failing to set any limits on other Russian weapons either.

Critics also say that Russia has cheated on its arms control commitments. But there is no evidence that Moscow has violated New START—in fact, Russia has stuck to its rules so far. What’s more, the treaty’s robust verification provisions guard against future cheating, which is one reason why the U.S. military supports it. Verification under New START makes it more likely that the U.S. government will detect Russian preparations to break their treaty commitments, providing time to address these issues through diplomacy. Robust verification actually deters cheating.

Given Beijing’s growing stature, shouldn’t New START cover China too?

China’s global influence is on the rise, but its stockpile of nuclear weapons is far smaller than that of either the United States or Russia. New START caps the Russian and U.S. arsenals at 1,550 deployed strategic warheads each. Beijing is estimated to have only a few hundred warheads and delivery systems that would fall under New START.

Neither U.S. nor Russian officials have suggested how China could be motivated to join them in limiting or further reducing these weapons. Washington and Moscow have not even hinted that they would be willing to negotiate reductions to levels even twice as high as China’s. Nor have they said what they might offer Beijing in return if it agreed to limit its potential build-up of any types of nuclear-capable forces. Given China’s role in East Asian and South Asian security dynamics, negotiations with Beijing on these issues would need to be widened to involve others, including at least India, Japan, and Pakistan.

Again, U.S. officials—in the Trump administration and Congress—have not addressed such issues, despite placing a priority on replacing New START with a multilateral accord rather than extending it.

What are the risks of letting New START expire?

Failing to extend New START would mean that the U.S. and Russian strategic nuclear arsenals would be unconstrained for the first time in several decades. The treaty limits the vast majority of weapons that each side would use in a large-scale nuclear conflict. It does so without negatively affecting other U.S. defense requirements, such as strategic deterrence of China, missile defense, or the modernization of nuclear and conventional capabilities. Furthermore, the areas of friction between the United States and Russia are regional—as the likeliest sources of U.S.-Russian conflict stem from Russian encroachment in Europe, perhaps against a NATO ally. This is yet another reason why U.S. military leaders judge that the U.S. long-range nuclear arsenal does not need to be completely unconstrained.

If New START expires, it would be difficult—if not impossible—for the U.S. intelligence community to compensate for the loss of insight that U.S. inspectors now have into Russian nuclear weapons bases and storage facilities, and the resulting up-to-date information on the whereabouts of Russian nuclear weapons.

What’s more, the timing is bad. The United States is just starting to update its nuclear weapons and infrastructure. Meanwhile, Russia has nearly finished its latest cycle of modernizing its arsenal after several years. It would be irresponsible to leave Russia unconstrained, while the U.S.-Russia relationship is filled with distrust and while Moscow is deploying more modern nuclear weapons.

The United States and Russia have no shared vision for arms control after New START, and they need time to think through this challenge. It would be better to do that with some nuclear guardrails still in place.

Carnegie does not take institutional positions on public policy issues; the views represented herein are those of the author(s) and do not necessarily reflect the views of Carnegie, its staff, or its trustees.