WAR MAY not pay, as British economist Norman Angell repeatedly claimed, but the lesson proved a hard one for states to learn. Even with the horrors of World War I fresh in their minds, European countries went into World War II just twenty-one years later. Until August of 1945, violent conflict punctuated the history of states, especially of those major and great.

When in short order the Soviet Union followed the United States into the nuclear business with “man of steel” Stalin and in due course “we will bury you” Khrushchev at the helm, many in the Western world thought that all hell would break loose. Robert Maynard Hutchins, boy president of the University of Chicago (he was thirty when he took over), and Bertrand Russell, eminent in mathematics and rhetoric, proclaimed that in the nuclear age, world government was the only alternative to world war. With nuclear weapons, war presumably meant that civilization would perish and we along with it. Instead, the alternative to world government proved to be nuclear deterrence, which banished war among the world’s major nations through the long years of the Cold War and ever since.

Certainly, violent conflict still exists, but it has been relegated to taking its course in the periphery of international politics. The United States, in particular, has been fond of beating up poor and weak states. In the twenty years dating from 1983, we invaded six of them, beginning and ending with Iraq. Yet since the end of World War II, states with nuclear weapons have never fought one another. Testing propositions against historical events has become a favorite indoor sport of social scientists. This is the only proposition that has passed every test. One might think that the best, in fact the only, peacekeeping weapon that the world has ever known would gain many fans. It does not seem to have done so.

WE NOW have a president who wants to free us from the atomic bomb in the hope of making the world a safer place. This “zero option” has intuitive appeal. Nuclear weapons are immensely destructive. No defense against them is possible. Why then should states not band together and agree to abolish them? Why is the zero option not the best choice?

Abolishing the weapons that have caused sixty-five years of peace would certainly have effects. It would, among other things, make the world safe for the fighting of World War III. Like any dominant power, America is a looming threat in the minds of many a leader. When the president of the United States identified three countries—Iraq, Iran and North Korea—as forming an axis of evil, which President George W. Bush did in January of 2002, and when he then ordered the invasion of one of them, what were the other two to think? They had to believe that they might be next. What to do? How can any state hope to deter a world-dominant power? To build a conventional defense against the United States is impossible. Moreover, throughout history conventional deterrence has repeatedly failed. Nuclear weapons are the only weapons capable of dissuading the United States from working its will on other nations.

To suggest to other states that America’s willingness to shrink its nuclear arsenal should induce them to follow the example, or should persuade them to give up their efforts to become nuclear states, is fanciful. For in spite of much Obama rhetoric, the United States shows no intention of dropping its nuclear forces below the second-strike level. The president, speaking to the people of the Czech Republic, promised that we will “take concrete steps toward a world without nuclear weapons.” He then followed that statement with this one: “Make no mistake: As long as these weapons exist, the United States will maintain a safe, secure and effective arsenal to deter any adversary, and guarantee that defense to our allies.” That is, we will, as we should, continue to maintain forces able to launch a devastating retaliatory blow even if struck first. Nuclear arsenals may be reduced to very small numbers, but if they remain at or above the second-strike level, the military relations of states continue unchanged.

If somehow world leaders blundered into an agreement to go to zero, what would any nuclear country with sensible leaders do? The answer can be given in one word: cheat. Nuclear weapons are small and light. They are easy to hide and easy to move. Nuclear warheads can be placed in small vans or small boats and sent across borders or into harbors. Because a ban on all nuclear weapons would be impossible to police and enforce, some countries would be tempted to break the rules. Since some might cheat, all would have a strong incentive to do so. Even worse, if the zero option were generally accepted, one state or another might eventually come to believe that it faced a threat to its very existence. A mad scramble to rearm with nuclear weapons would then take place. As Thomas C. Schelling long ago wrote, “Short of universal brain surgery, nothing can erase the memory of weapons and how to build them.”¹

WITH THE dawn of the nuclear age, peace has prevailed among those who have the weapons or enjoy their protection. Those who like peace should love nuclear weapons. They are the only weapons ever invented that work decisively against their own use. Those who advocate a zero option argue in effect that we should eliminate the cause of the extensive peace the nuclear world has enjoyed.

India and Pakistan provide an object lesson. When they tested their warheads in May of 1998, journalists, academics and public officials predicted that war and chaos on the subcontinent would ensue. The result, as I expected, was to ensure a prolonged peace between countries that had fought three wars since independence and continued for a time to spill blood in the conflict over Kashmir.

That countries with nuclear capabilities do not fight wars against one another is a lesson we should have learned. The proposition has held exactly where the prospects for war seemed the brightest, for example, between the United States and the Soviet Union, between the Soviet Union and the People’s Republic of China, and between India and Pakistan. New nuclear states are often greeted with dire forebodings: Is the government stable? Are the rulers sensible? The answers may be disconcerting. Yet every new nuclear nation, however bad its previous reputation, has behaved exactly like all of the old ones. The effect of having nuclear weapons overwhelms the character of the states that possess them. Countries with nuclear weapons, no matter how mean and irrational their leaders may seem to be, no matter how unstable their governments appear to be, do not launch major conventional attacks on other countries, let alone nuclear ones. Even conventional attacks can all too easily escalate out of control and lead to an exchange of nuclear warheads. With conventional weapons, countries worry about winning or losing. With nuclear weapons, countries worry about surviving or being annihilated. Nuclear weapons induce caution all around: think of the Cuban missile crisis, or think of the external behavior of China during the frightful decade of the Cultural Revolution.

THESE DAYS, everyone favors transparency. On the nuclear front the United States is transparent enough. Transparently, it is in America’s interest to get would-be nuclear states to foreswear the capability. Transparently, it is in America’s interest to get presently nuclear states to reduce or, better yet, eliminate their warheads. We are after all the world’s dominant conventional power and have been for years. Are we willing to reduce the number of our nuclear weapons? Sure; we have far more warheads than deterrence requires. Would we be willing to reduce the number of our strategic warheads below what we think necessary for a second-strike capability? Obviously not. We are transparent on that one as well.

¹ Thomas C. Schelling, “The Role of Deterrence in Total Disarmament,” Foreign Affairs 40, no. 3 (April 1962): 392.