In talking about arms control during the Cold War, I will focus on the U.S.-Soviet Strategic Arms Control aspect of it. This is of course by no means the whole picture; it leaves out, among other things, the Nonproliferation Treaty. But the U.S.-Soviet strategic relationship was what occupied our attention most of the time.

It is only a slight exaggeration to say that the Cold War was really about nuclear weapons. The nuclear age and the Cold War begin at roughly the same time. Nuclear weapons defined in important respects the Cold War relationship between the two main protagonists. It was nuclear weapons that made the Cold War different from the great political rivalries of the past. The nuclear dimension was rarely if ever lost sight of by leaders, and in publics it produced a pervasive nuclear anxiety, particularly at the beginning of the Cold War. Every U.S. president since the Cold War began felt compelled to try to find in some way ways to control nuclear weapons—even though most of them were at the same time also building up our nuclear arsenal.

If the results were modest until the very end of the Cold War, they were not without significance. In a sense, the impulse to control the new and terrifyingly destructive power of nuclear weapons preceded the weapons themselves. Well before the Trinity test, some of the scientists involved in the Manhattan Project fretted about their larger responsibility to humanity. Niels Bohr among others lobbied to open early discussions with the Russians in order to establish postwar international control of nuclear weapons, an idea rapidly squelched by Winston Churchill. The idea of international control resurfaced in what might be called the first nuclear arms control proposal of the Cold War, the Baruch plan, which the U.S. put forward in 1946. The Baruch plan would have created a supranational body, the Atomic Development Agency, with a global monopoly over virtually the whole field of atomic energy and the right of intrusive inspection. But the Russians were even then hard at work on their own nuclear weapon and had not the slightest interest in giving it up, so the Baruch plan went nowhere.

Nearly a decade passed before the next serious effort at arms control, a decade that marked the height of the Cold War with all its crises and tensions, the Korean War and the Berlin blockade. The Soviets had by then acquired their own bomb, which added to the underlying nuclear anxiety. To the extent nuclear arms control was considered at all, it took the form of empty and propagandistic schemes for abolishing the bomb in the context of complete and general disarmament.

It was ironically the invention of thermonuclear weapons that provided the impulse for the first real arms control agreement, the Limited Test Ban Treaty. Public concerns about the fallout from testing, which were already acute, intensified with the spectacular tests of these vastly more destructive weapons, in particular the U.S. Bravo series. Public protests and pressures to end testing increased, but it took eight years, some very difficult negotiations, and the combined efforts of two U.S. presidents before a Soviet proposal for a standalone ban on testing, first put forward in 1955, became the landmark treaty of 1963, which banned all testing in the atmosphere, the oceans, and space.

President Eisenhower said that the deepest disappointment of his presidency was his inability to conclude this treaty, and it fell to JFK to finally do so. But this did not happen until we had gone, as the phrase goes, eyeball-to-eyeball with the Soviets during the Cuban Missile Crisis. It may indeed have been this sobering experience that pushed the two leaders, Kennedy and Khrushchev, to bring the negotiations to a conclusion.

In many ways the 1963 LTBT set the pattern for how arms control was to proceed during the Cold War. It was an important milestone, unquestionably. It showed that we and the Soviets could find common ground on nuclear issues, despite our larger political hostility. But it did nothing to slow the rapidly increasing numbers of nuclear weapons on both sides. Still less did it do anything to slow or constrain nuclear testing. Testing simply went underground. Fifty-four percent of all U.S. tests between 1945 and 1980 took place after 1963, and today the goal of abolishing all nuclear tests remains unrealized and controversial.

By then, of course, it was clear that nuclear weapons were here to stay. We came to regard them as a fearsome necessity designed to ward off not only a Soviet nuclear attack but also, more plausibly, a conventional attack by superior Warsaw Pact forces on NATO forces in Europe, to which the U.S. was committed, at a point purposely left vague, to respond with its nuclear weapons. It was our firmly held belief that nuclear weapons kept the peace by forestalling an otherwise inevitable conventional war in Europe. And indeed, if we look at the historical record of how great power rivalries have resolved themselves in the past, I’m not prepared even today to say that this was wrong.

Thus, nuclear weapons came in some sense to be regarded as a stabilizing factor. We lost any interest in abolishing them or even in the pretense that this would be a good thing. But the numbers continued to grow, and by the late 1960s the Soviets had built up their arsenals of ICBMs to levels approaching ours. People worried that if we did not stop the inexorable rise of Soviet weapons, they would soon outpace us.

Out of this concern were born the Strategic Arms Limitation Talks (SALT), which produced two agreements, SALT I and SALT II. Limitation was the operative word, because at that time there was really no thought of trying to agree on reductions. Our goal was to slow, and ultimately halt, the pace of increase.

The SALT I agreement, which was signed in 1972 during the Nixon administration, in fact included two agreements: the ABM Treaty and the “Interim Agreement.” Under the ABM Treaty, with the exception of two ABM sites allowed to each side, the U.S. and USSR renounced the idea of building nationwide defenses against nuclear attack.

The ABM Treaty has assumed iconic status to both its supporters and detractors as the embodiment of the strategy of mutual assured destruction (MAD), and was elevated into a cornerstone of strategic stability. It was unquestionably a major achievement, but its origins were rather more mundane than later interpretations suggest. We had an antimissile system that wouldn’t work. that was hugely expensive, and which the Senate was refusing to fund. The Soviets, who did have an ABM system, were happy to close off an expensive technological race with the U.S. that they were sure to lose.

Unquestionably, mutual deterrence, and a condition of mutual vulnerability were the existential realities of the Cold War. At one level, this reality was probably accepted by both sides. In this sense, the ABM Treaty codified a fact of life rather than a choice of doctrine, particularly since the Soviets never really bought into MAD, at least in the sense it was understood by American strategists.

The second agreement, the Interim Agreement, froze ICBMs and submarine-launched ballistic missiles (SLBMs) at existing levels, limits that have been rightly characterized as “temporary, high, and incompletely agreed.” There were some serious omissions. The agreement failed to limit the growth of Soviet heavy missiles, a particular bugaboo of American strategic planners. More seriously for future stability, it did nothing to constrain the new technology of multiple independently targetable reentry vehicles (MIRVs). This allowed a single missile to carry up to 8–10 warheads. Once MIRVs were introduced, first by us and then by the Soviets, the total numbers of weapons were to rise to really stratospheric levels. But the Interim Agreement said nothing about MIRVs.

Then too, the Interim Agreement froze the numbers at higher levels for the Soviets than the U.S., a fact that was more important because of political perceptions than it was militarily.

SALT I was nonetheless ratified, and new negotiations began immediately for a successor treaty. However, these were not completed until the very end of the Carter administration. SALT II was everything SALT I was not. It provided for equal levels between the two sides, heavy bombers were included, it dealt with such problems as heavy missiles and MIRVs, it was carefully and precisely drafted, a lawyer’s dream in many ways. The only problem was that it capped weapons at levels far above existing ones, so that the Soviets actually had the right to deploy an astonishing 1,200 additional weapons.

SALT II was greeted by a storm of criticism which ultimately reflected less its own inadequacies than a radical change that had occurred in the political climate in the seven years it took to negotiate it. By 1979, the Kissinger-Nixon d‚tente was discredited. It was felt that the Soviets were on the march throughout the globe, while we were in retreat in Vietnam and elsewhere. People worried about Soviet strategic superiority and something called the “window of vulnerability.” The final straw was the Soviet invasion of Afghanistan in December 1979, after which President Carter withdrew the treaty from the Senate. That was in effect the end of arms control during the Cold War proper. There was to be a long hiatus before arms control negotiations got going again in earnest, and by that time, Gorbachev’s arrival on the scene signaled the beginning of the end of the Cold War.

So what can we say about arms control during this period of the Cold War? Its achievements were modest; it’s easier to say what it did not achieve than what it did. It did not end or even slow the arms race, either quantitatively or qualitatively. Numbers continued to rise. Neither side gave up a single weapon system that it really wanted. It did not reduce defense spending; to the contrary, both SALT and I and SALT II were purchased at the price of a significant increase in the U.S. defense budget. It is sometimes claimed that it helped to stabilize relationships between the two superpowers, but this claim does not really withstand scrutiny. Arms control was a very fragile bloom, and it was blown off course by political winds on numerous occasions. Thus, Eisenhower’s hopes for signing the LTBT were dashed with the downing of the U2 and the cancellation of his summit with Khrushchev. LBJ had hoped to open the SALT negotiations in 1968, but the Soviet invasion of Czechoslovakia put an end to that. The Soviet invasion of Afghanistan crushed SALT II. Moreover, the agreements themselves were often sources of bitter controversy.

But if we accept that it was unrealistic to think that arms control could transcend the political hostility of the broader relationship, we can see that its modest contribution was significant in its own way. First, the very fact of the dialogue between the two nuclear-armed superpowers was reassuring to publics and perhaps in some ways to the participants themselves. It helped, however minimally, to lessen the nuclear anxiety to which I have alluded. This nuclear anxiety certainly increased during periods when there was no arms control negotiation going on. The agreements themselves provided a modicum of transparency and predictability. Moreover, a decade of arms control negotiations created a small community of experts on either side who among themselves created the building blocks—the terms, the definitions, the “counting rules”—that were to provide the foundation for the later, more lasting agreements of the Reagan-Gorbachev era.

Finally, even though Ronald Reagan had sharply attacked the SALT II agreement during his 1980 presidential election campaign and was never to ratify it, his administration observed the treaty’s limits by mutual agreement with the Soviets until 1986.

And so we come to the final phase, the winding down of the Cold War, the Reagan-Bush-Gorbachev era. Even those of us who were not particular admirers of President Reagan will concede that he has emerged as a more complex figure than he seemed at the time. Among his more intriguing characteristics was his very genuine abhorrence of nuclear weapons. However, little during Reagan’s first term prefigured the nuclear abolitionist of the Reykjavik summit. To the contrary, the often bellicose rhetoric emanating from Washington, the suggestion that a nuclear war could be fought and won in Europe, the build-up of our nuclear arsenal were developments deeply unnerving to public opinion and inspired the creation of a nuclear freeze movement that brought out half a million people in Central Park in the early 1980s. There was not a single high-level meeting between the U.S. and Soviet leaders during this period.

If Reagan’s insistence that arms control must produce real reductions was not unreasonable, his fantastic vision of a missile shield that would render nuclear weapons obsolete, the so-called Strategic Defense Initiative (SDI), was ably manipulated by the opponents of arms control in his administration into a permanent blocking device for any arms control agreement at all.

Gorbachev’s arrival on the scene changed this dynamic. It was not Ronald Reagan’s firmness, our outsized defense budgets, or the pressure of SDI that brought the Cold War to an end, but rather Gorbachev, who understood how counterproductive the Soviet military build-up of the 1970s- 80s had been—bankrupting the Russian economy, generating hostility in the outside world, and generally isolating Moscow. He now sought, in parallel with the domestic reforms known as perestroika, to give a new direction to Russia’s relations with the outside world and to reduce the weight of military expenditures on the Russian economy—among other things, through arms control agreements. In Reagan, he was surprisingly to find a supportive interlocutor.

And so, for a time, we find Gorbachev throwing out arms control proposals like a sparkler, for the abolition of this, deep reductions of that, and so on. This energy resulted, among other things, in the famous Reykjavik meeting of October 1986, where agreement was reached on a breath-taking series of proposals, including the elimination of all nuclear weapons, only to have everything fall apart at the end over SDI. Many people, including our European allies, were quite relieved.

In the end, only the Intermediate Nuclear Forces (INF) Agreement survived the wreckage of Reykjavik. This treaty, which was signed in December 1987, eliminated an entire class of weapons, the intermediate-range nuclear weapons—on the U.S. side, the Pershings and ground-launched cruise missiles (GLCMs) that had been so recently deployed in Europe in the face of massive political opposition, and on the Russian side, the SS 20s.

But it was not until the George H.W. Bush administration that we succeeded in closing the deal on the far more important strategic weapons, the long-range missiles on either side. The START I Treaty was signed in 1991 and ratified three years later, thus beginning a ten-year process of reductions that resulted in the destruction of tens of thousands of nuclear weapons. A second treaty, START II, was signed in the closing days of the G.H.W. Bush administration. In these two treaties, we achieved goals we had been pursuing for twenty years—including deep reductions, the elimination of heavy missiles, intrusive verification and the like.

But then something funny happened. In the early 1990s, the USSR ceased to exist, the Cold War was over, and we suddenly ceased to care very much about these things anymore. We no longer worried about the Soviet strategic threat; the urgency was no longer there. START I was not ratified until three years after it was signed, in 1994; START II was never ratified at all. Real arms control, it seemed, became possible only when it was no longer necessary. But it would be wrong to argue, as some have, that these treaties were unnecessary or redundant because the Soviets would have reduced on their own, or to underestimate their importance because the Cold War had ended. The treaties provided a useful framework for the transformations taking place and an indispensable instrument for managing the end of the Cold War and the decline of Soviet power. They locked into place the reductions as well as transparency and verification mechanisms, and they remain very important.

Today the Cold War is long over, but there are still thousands of strategic weapons out there. Ninety percent of them belong to the U.S. and Russia. After the languid pace of arms control during the last eight years, further reductions are now an urgent task.