Writing on October 8 for The Washington Post’s “PostEverything” site, Stephen Rademaker proposed that President Obama penalize Russia for its aggression against Ukraine by suspending reductions to be made under the 2010 New Strategic Arms Reduction Treaty (New START). The president should do more to assist Ukraine, including providing greater military assistance. But tampering with New START is not in the United States’ interest: it could cause the treaty to unravel, at a time when Russia is building new strategic weapons—and the United States is not.

Rademaker wrote that President Jimmy Carter asked the Senate to suspend consideration of the 1979 Strategic Arms Limitation Treaty (SALT II) to punish the Soviet Union for its invasion of Afghanistan and cited that as an example Obama should emulate. Actually, Carter had no choice. Under the circumstances, the Senate would have refused to ratify SALT II.

Carter launched a diplomatic “press” on Moscow and armed the Afghan resistance, policies that President Ronald Reagan continued. Rather than suspend arms control, however, Reagan abided by the SALT II limits for six years and launched new negotiations with the Soviets to reduce strategic arms and intermediate-range missiles.

The U.S. and EU Response to Russian Aggression

Over the past six months, the United States and European Union have responded to Russia’s aggression against Ukraine with tough economic sanctions. They have caused capital flight from Russia to soar, brought the ruble to new lows and forced Russian companies to turn to their government for tens of billions of dollars of credit financing. The sanctions go far beyond what the West imposed on the Soviet Union in the 1980s.

In proposing to suspend New START reductions, Rademaker asserted that the treaty forces only the United States to reduce. True, Russian strategic forces in the 1990s and 2000s steadily declined in numbers as the Russian defense budget was starved of funds.

The Kremlin’s Strategic Force Modernization

That began changing some years ago, as greater budget revenues enabled the Kremlin to spend more on strategic force modernization. Today, the Russians are deploying new Borey-class ballistic missile submarines, new Bulava submarine-launched ballistic missiles and new Topol-M and Yars intercontinental ballistic missiles.

Those who claim that New START requires only the United States to come down to the treaty’s limit of 1,550 deployed strategic warheads should check the most recent New START data exchange: as of September 1, Russia had 1,643 deployed strategic warheads—one more than the United States. (The treaty’s limits are to be reached by February 2018.)

The United States still holds a lead in deployed strategic missiles and bombers. But serious analysts would agree that the number of what goes up—missiles—matters far less than what comes down—warheads. Indeed, the George W. Bush administration in which Rademaker served sought to limit only warheads, not missiles (or bombers).

Suspending New START Reductions is a Risky Game

Suspending New START reductions would make little sense. Such a move could set in motion a risky and potentially dangerous game. The Kremlin might well retaliate. One Russian official last spring raised the prospect of suspending treaty inspections. It is not in the United States’ interest to start down a path that could lead to New START unraveling.

The treaty’s data exchanges, notifications and inspections provide critical transparency about Russian strategic forces, while its limits provide hard caps on their size. It is in both sides’ interest to keep the strategic arms competition constrained and predictable. That becomes more important now, when Washington and Moscow find themselves in a more confrontational relationship over Ukraine.

Were New START to come undone, Russia could well continue its ongoing strategic production lines. A new strategic arms race is not an inviting prospect. While the Pentagon has its strategic modernization plans, new American ballistic missile submarines and long-range bombers will only begin to appear in the late 2020s.

Moscow thus would enjoy a running head-start in any new strategic arms race. And doubts have already arisen about whether the U.S. defense budget can afford even the current modernization plans.

So Carter’s handling of SALT II does not offer a good example for Obama. He should look instead to Reagan. Obama should maintain sanctions on Moscow until it becomes part of the solution rather than the source of the problem for Ukraine, and he should provide Kyiv with defensive weapons. But he should not play a risky game with the New START Treaty, whose implementation remains very much in the U.S. national interest.