When U.S. senators voted to reject the Comprehensive Test Ban Treaty, they took a giant step backward. In today’s era of relative peace, they allowed partisan rancor and atomic fears to forestall real progress.

Even in the Cold War’s darkest moments, American policy makers recognized that slowing down the nuclear arms race was essential to preserving both international security and the quality of national life. Ignoring that lesson risks creating a more dangerous future.

On July 16, 1945, J. Robert Oppenheimer watched an eight-mile-high mushroom cloud rise into the New Mexico sky with a mixture of pride and foreboding. The Manhattan Project had solved a daunting scientific challenge, but Oppenheimer recalled an apocalyptic passage from Hindu scripture: “I am become death, the destroyer of worlds.”

Since that moment, the world has lived in the nuclear shadow. Within four years of the 1945 bombings of Hiroshima and Nagasaki, with their 200,000 fatalities, the U.S.S.R. developed an atomic bomb and the Cold War produced a massive arms race. Soon both superpowers created even more devastating hydrogen bombs. By 1972, the United States and the Soviet Union possessed enough nuclear warheads to explode the equivalent of 15 tons of radioactive TNT for every person alive on the face of the earth.

Yet, even in an international climate far more hostile than the one we face today, American leaders took important steps to control the delicate balance of terror. Dwight D. Eisenhower insisted that the United States maintain a stockpile sufficient to deter a Soviet strike, but also argued that unlimited arms racing would jeopardize world peace and damage American society. “Every gun that is made, every warship launched, every rocket fired,” he warned, “signifies, in a final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed.”

As early as 1958, Eisenhower and Soviet Premier Nikita Khrushchev agreed to an informal moratorium on atmospheric nuclear tests and, a full 30 years before the recent Senate vote, began discussions for a comprehensive test ban treaty. When the Soviets shot down an American U-2 spy plane over Russian territory, those hopes faded. But they did not die.

Long before President Clinton signed the Comprehensive Test Ban Treaty in 1996, John F. Kennedy and Richard Nixon made concrete efforts to back away from the nuclear threshold. Despite their ideological differences, both understood what today’s senators have forgotten — that the risk of nuclear war demands the risk of negotiation.

After facing the sobering possibility of global devastation in the Cuban missile crisis, Kennedy argued that although a deterrent force was necessary Americans could “seek a relaxation of tensions without relaxing our guard.” His efforts resulted in the U.S.-Soviet Limited Test Ban Treaty of 1963, a measure that banned the explosion of atomic devices in the atmosphere, outer space, and under the oceans. 

In 1972, Nixon and Leonid Brezhnev signed the first SALT (Strategic Arms Limitation Talks) Treaty, a measure that, for the first time, limited the number of nuclear missiles deployed by each side. The Senate approved it by a vote of 88 to 2, an endorsement that contrasts sharply with this month’s decision.

The Cold War’s most stunning arms control gains were made when Ronald Reagan, hero of the same party that just turned its back last week on the international treaty, accepted a Soviet proposal. In 1987, Reagan and Mikhail Gorbachev agreed to destroy all the intermediate and short-range nuclear missiles their nations had stationed in Europe and set up a verification system providing for on-site inspections. For the first time, diplomacy led not just to effective limits but also provided for the secure elimination of an entire class of weapons. By easing U.S.-Soviet tension, that action also helped promote the Cold War’s final thaw.

American security, these leaders knew, depended on the security of others. Agreements to curb the nuclear arms race were difficult and never risk-free, but their advantages outweighed the real dangers of unchecked escalation. By failing to support an international accord to control nuclear arms, Senate Republicans have ignored the hard-won lessons of the Cold War.

As others have been quick to point out, if the most formidable nuclear power on earth will not take a stand against further weapons development, other nations will be far less likely to do so. It takes courage to seek peace and wisdom to know that certain solutions will not be found in an uncertain world.