Nuclear Deterrence for the Future

New Visions for National Security

THOMAS C. SCHELLING

Nuclear Deterrence for the Future

Although the geopolitical map of the future differs significantly from that of the past 60 years, deterrence remains a linchpin of global security.

The most significant event of the past 60 years is the one that did not happen: the use of a nuclear weapon in conflict. One of the most important questions of the next 60 years is whether we can repeat this feat.

The success that we have had in avoiding the construction and deployment of nuclear weapons by a large number of nations has been far better than anybody anticipated 40 or 50 years ago. Likewise, the fact that nuclear weapons have not been used is rather spectacular.

The British scientist, novelist, and government official C.P. Snow was quoted on the front page of the New York Times in 1960 as saying “unless the nuclear powers drastically disarmed, thermonuclear war within the decade was a mathematical certainty.” I think he associated with enough scientists and mathematicians to know what mathematical certainty was supposed to mean. We now have had that mathematical certainty compounded more than four times without any use of nuclear weapons.

When Snow made that statement, I did not know anyone who thought it was outrageous or exaggerated. People were really scared. So how did we get through these 60 years without nuclear weapons being used? Was it just plain good luck? Was it that there was never any opportunity? Or were there actions and policies that contributed to this achievement?

The first time when it seemed that nuclear weapons might be used was during the Korean War, when U.S. and South Korean troops retreated to the town of Pusan at the southern tip of Korea. The threat was serious enough that Britain’s prime minister flew to Washington with the announced purpose of persuading President Truman not to use nuclear weapons in Korea.

The Eisenhower administration, or at least Secretary of State John Foster Dulles, did not like what he called the taboo on the use of nuclear weapons. He said “somehow or other we must get rid of this taboo on nuclear weapons. It is based on a false distinction.” And the president himself said “if nuclear weapons can be used for purely military purposes on purely military targets, I don’t see why they should-n’t be used just as you would use a bullet or anything else.” The United States even announced at a North Atlantic Treaty Organization (NATO) meeting that nuclear weapons must now be considered to have become conventional.

U.S. policy had changed considerably by the time Lyndon Johnson became president. In 1964 he said, “Make no mistake. There is no such thing as a conventional nuclear weapon. For 19 peril-filled years no nation has loosed the atom against another. To do so now is a political decision of the highest order.”

Those 19 peril-filled years are now 60 peril-filled years. President Kennedy started, Johnson continued, and Secretary of Defense Robert McNamara spearheaded a powerful effort to build up enough conventional military strength within the NATO forces so that they could stop a Soviet advance without the use of nuclear weapons. Both Kennedy and Johnson had a strong aversion to the idea of using nuclear weapons.

During the 1960s, the Soviets officially ridiculed the idea that there could be a war in Europe that did not instantly— in their words, automatically—go nuclear, but their actions were very different from their public announcements. They spent huge amounts of money developing conventional weaponry, especially conventional air weaponry in Europe. This investment would have made no sense if a European war were bound to become nuclear, especially from the outset. It seems to me that the Soviets recognized the possibility that the world’s nations might get along without actually using nuclear weapons, no matter how many of them were in the stockpiles.

I find it noteworthy that as far as I know, the United States did not seriously consider using nuclear weapons in Vietnam. Of course, I’ll never really know what was in Richard Nixon’s or Henry Kissinger’s mind, but at least we know that they were not used.

Remarkably, Golda Meier did not authorize the use of Israel’s nuclear weapons when the Egyptians presented excellent military targets. At one point, two whole Egyptian armies were on the Israeli side of the Suez Canal, and there were no civilians anywhere in the vicinity. This was a perfect opportunity to use nuclear weapons at a time when it was not clear that Israel was going to survive the war. And yet they were not used. We can guess at some of the reasons, but I think it was Meier’s long-range view that it would be wise to maintain the taboo against the use of nuclear weapons because eventually any country could become a nuclear target.

When Great Britain was defending the Falkland Islands, it had several opportunities when nuclear weapons might have been effective, but Margaret Thatcher decided that they were not an option. The Soviets fought and lost a degrading and demoralizing war in Afghanistan without resorting to nuclear weapons. Some observers have argued that the Soviets had no viable targets; I believe that they did have opportunities but nevertheless decided against using nuclear weapons. I believe that the underlying rationale against their use was the same for these countries as it was for Lyndon Johnson: The many peril-filled years in which nuclear weapons were not used had actually become an asset of global diplomacy to be treasured, preserved, and maintained.

Maintaining the streak

Will the world be able to continue this restraint as more nations acquire nuclear weapons? Since Lyndon’s Johnson statement, India and Pakistan have developed nuclear weapons. Even in my lifetime, I expect to see a few more countries do so. How do we determine whether these new nuclear powers share the commitment to avoid the use of these weapons?

From a U.S. perspective, two ideas are worth considering. The country should reconsider its decision not to ratify the Comprehensive Test Ban Treaty. It was an opportunity to have close to 180 nations at least go through the motions of supporting the principle that nuclear weapons are subject to universal abhorrence. Nominally, the treaty was about testing, but I believe that it could have served a more fundamental purpose by essentially putting another nail in the coffin of the use of nuclear weapons.

I also believe that even if U.S. leaders believe that there are circumstances in which they would use nuclear weapons, they should not talk about it. And if they want to develop new weapons, they should do so as quietly as possible—even avoiding congressional action if possible. The world will be less safe if the United States endorses the practicality and effectiveness of nuclear weapons in what it says, does, or legislates.

The National Academy of Sciences Committee on International Security and Arms Control (CISAC), the Ford Foundation, the Aspen Institute, and other institutions have sponsored numerous international meetings on arms control, and these meetings have almost always included representatives of India and Pakistan. I believe that it was extremely important for them to hear at firsthand from U.S. scientists and political leaders about the dangers associated with the use of nuclear weapons. I believe that India and Pakistan also learned from watching Cold War leaders forego the use of those weapons because they feared where it might lead. Because I think that India and Pakistan have absorbed some of the lessons of this experience, I worry less about what might develop in an India-Pakistan standoff.

Now it is important to teach the Iranians that if they do acquire nuclear capability, it is in their national interest to use such weapons only as a means to deter invasion or attack. The president of Iran was recently quoted as saying that Iran still intended to wipe Israel off the face of the earth. My guess is that if they think about it, they are not going to try to do it with nuclear weapons. Israel has had almost a half century to think about where to store its nuclear weapons so that it would be able to launch a coun-terattack if its existence is threatened. Iran does not want to invite a nuclear attack. Every Iranian should be aware that the use of nuclear weapons against Israel or any other nuclear power is an invitation to national suicide. It is important that not only a few intellectuals in Iran understand this, but that people throughout the country share this awareness. I would like to see a delegation of Iranians participating in future CISAC meetings.

All new nuclear powers would benefit from knowing that it took the United States 15 years after the development of nuclear weapons to begin to think about the security and custody of the weapons themselves. This did not happen until Robert McNamara had his eyes opened by a study done by Fred Ikle of the RAND Corporation that revealed that U.S. nuclear weapons did not even have combination locks on them, let alone any police dogs to guard them on German airfields. McNamara initiated what became known as “permissive action links.” It took about four years to have the permissive action links developed to his satisfaction and then finally installed on the land-based warheads. If the Iranians do develop nuclear weapons, it is critical that it not take them 15 years to think about the custodial problems. Will control be granted to the army, navy, air force, or palace guard? Will security be adequate at storage facilities? We have witnessed enough instability across the globe to know that governments fail and that the branches of the armed forces sometimes take different sides in civil conflicts. Iran needs to think through what will happen to the weapons in the event of a government failure. Will some part of the government or military be able to maintain control, or will they watch Israeli commandos arrive to take charge of the weapons?

A nuclear Iran would need to act rapidly on questions of security, custody, and the technological capacity to disarm the weapons if they lose control of them. CISAC could be of enormous help to the Iranians in relaying the lessons from decades of U.S. experience in learning how to manage custody of nuclear weapons.

An even more important task will be to prepare for the extremely remote possibility that a terrorist group could acquire such weapons. It will be essential but very difficult to persuade them that nuclear weapons are valuable primarily as means of persuasion and deterrence, not destruction.

About 20 years ago, I began thinking about how a terrorist group might use a nuclear weapon for something other than just blowing up people. A good example occurred during the Yom Kippur war of 1973. The United States resupplied Israel with weapons and ammunition, but the United States was not allowed to fly from European NATO countries or to refuel its planes in Europe. All of the refueling was done in the Azores. It struck me then that if I were a pro-Palestinian terrorist and had a nuclear weapon, I would find a way to make clear that I had it and that I would detonate it near the air fields in the Azores if the United States did not stop landing planes loaded with ammunition for Israel. This strategy had a number of fallback positions: If it failed to deter the United States from refueling in the Azores, it might deter Portugal, which owned the Azores, from allowing the refueling to take place, and if that failed, it might deter the individuals working at the airport and doing the refueling. If we ever have to face the prospect of nuclear-armed terrorists, I want them to be thinking along these strategic lines rather than thinking about attacking Hamburg, London, or Los Angeles.

My hope for CISAC is that it will see its mission broadly: educating itself, U.S. leaders, and anyone who will be in a position to influence the decision to use a nuclear weapon. Thinking of extending this mission to Iran is difficult, and to North Korea even more so. I think it is important to keep in mind that if terrorists do acquire nuclear weapons, it would probably be by constructing them after acquiring fissile material, and that means that there is going to be quite a high-level team of scientists, engineers, and machinists of all kinds working over a significant period of time, probably in complete seclusion from their families and jobs with nothing to do but think about what their country and other countries are going to do once a bomb is ready. And I think they will probably come to the conclusion that the last thing they want to do is waste it killing Los Angelenos or Washingtonians. I believe they will think about sophisticated strategic ways to use a weapon or two or three if they have them.

This means we may be living in a world for the next 60 years in which deterrence is just as relevant as it was for the past 60 years. One difference will be that the United States will find itself being deterred rather than just deterring others. Although the United States likes to think of itself as always in the driver’s seat, in reality it was deterred by Soviet power from considering the use of nuclear weapons in several instances. I believe that the United States did not seriously consider rescuing Hungry in 1956 and Czechoslovakia in 1968 because it was sufficiently deterred by the threat of nuclear war.

My hope is that the United States will continue to succeed in deterring others from using nuclear weapons, and that others will succeed in deterring the United States.


Thomas C. Schelling (), Distinguished University Professor at the University of Maryland, won the 2005 Nobel Prize in Economics.