Thomas Schelling opens the 2008 edition of his Arms and Influence with a new preface:
The world has changed since I wrote this book in the 1960s. Most notably, the hostility, and the nuclear weapons surrounding that hostility, between the United States and the Soviet Union—between NATO and the Warsaw Pact—has dissolved with the dissolution of the Soviet Union and the collapse of the Warsaw Pact. A somewhat militarily hostile Russia survives the Cold War, but nobody worries (that I know of) about nuclear confrontations between the new Russia and the United States.
The most astonishing development during these more than forty years—a development that no one I have known could have imagined—is that during the rest of the twentieth century, for fifty-five years after Hiroshima and Nagasaki suffered the world’s first nuclear bombs, not a single nuclear weapon was exploded in warfare. As I write this in early 2008, it is sixty-two and a half years since the second, and last, nuclear weapon exploded in anger, above a Japanese city. Since then there have been, depending on how you count, either five or six wars in which one side had nuclear weapons and kept them unused.
[…]
Nuclear weapons were not used in the United Nations’ defense of South Korea. They were not used in the succeeding war with the People’s Republic of China. They were not used in the U.S. war in Vietnam. They were not used in 1973 when Egypt had two armies on the Israeli side of the Suez Canal. They were not used in the British war with Argentina over the Falkland Islands. And, most impressively, they were not used by the Soviet Union when it fought, and lost, a protracted, demoralizing war in Afghanistan.
This “taboo,” as it has come to be called, is an asset to be treasured. It’s our main hope that we can go another sixty years without nuclear war.
The nonproliferation program has been more successful than any student of the subject would have thought likely, or even possible, at the time this book was written. There are, in 2008, nine, possibly going on ten, nations that have nuclear weapons. When this book was being written, serious estimates suggested that three or four times that number would have nuclear weapons within the century. This outcome partly reflects successful policy and partly reflects the loss of interest in nuclear electric power, especially after the explosion in Ukraine of the Chernobyl reactor complex in 1986.
[…]
Smart terrorists—and the people who might assemble nuclear explosive devices, if they can get the fissionable material, will have to be highly intelligent—should be able to appreciate that such weapons have a comparative advantage toward influence, not simple destruction. I hope they might learn to appreciate that from reading this book.
[…]
Actually, I found the first sentence of the original preface to be even more portentous than I could make it in the 1960s. “One of the lamentable principles of human productivity is that it is easier to destroy than to create.” That principle is now the foundation for our worst apprehensions.
I had to coin a term. “Deterrence” was well understood. To “deter” was, as one dictionary said, to “prevent or discourage from acting by means of fear, doubt, or the like,” and in the words of another, “to turn aside or discourage through fear; hence, to prevent from action by fear of consequences,” from the Latin to “frighten from.” Deterrence was in popular usage not just in military strategy but also in criminal law. It was, complementary to “containment,” the basis of our American policy toward the Soviet bloc. But deterrence is passive; it posits a response to something unacceptable but is quiescent in the absence of provocation. It is something like “defense” in contrast to “offense.” We have a Department of Defense, no longer a War Department, “defense” being the peaceable side of military action.
But what do we call the threatening action that is intended not to forestall some adversarial action but to bring about some desired action, through “fear of consequences”? “Coercion” covers it, but coercion includes deterrence—that is, preventing action—as well as forcing action through fear of consequences. To talk about the latter we need a word. I chose “compellence.” It is now almost, but not quite, part of the strategic vocabulary. I think it will be even more necessary in the future as we analyze not just what the United States—“ we”—needs to do but how various adversaries—“ they”—may attempt to take advantage of their capacity to do harm.
We have seen that deterrence, even nuclear deterrence, doesn’t always work. When North Korea attacked the South, it wasn’t deterred by U.S. nuclear weapons; nor was China deterred from entering South Korea as U.S. troops approached the Chinese border (and the United States was not deterred by Chinese threats to enter the fray). Egypt and Syria in 1973 were not deterred by Israeli nuclear weapons, which they knew existed. Maybe Egypt and Syria believed (correctly?) that Israel had too much at stake in the nuclear taboo to respond to the invasion by using nuclear weapons, even on Egyptian armies in the Sinai desert with no civilians anywhere near.
But “mutual deterrence,” involving the United States and the Soviet Union, was impressively successful. We can hope that Indians and Pakistanis will draw the appropriate lesson. If this book can help to persuade North Koreans, Iranians, or any others who may contemplate or acquire nuclear weapons to think seriously about deterrence, and how it may accomplish more than pure destruction, both they and we may be the better for it.