President Harry Truman, who told reporters he didn’t lose any sleep over the decision to drop the A-bombs (the alternative, an invasion of Japan, would have caused the deaths of thousands of American soldiers), grew more solemn once he read the reports of their devastation. On July 21, 1948, at a private meeting with a few top generals and David Lilienthal, the Atomic Energy Commission’s chairman, Truman, looking down at his desk reflexively, spoke in a way he never did in public:
I don’t think we ought to use this thing unless we absolutely have to … You have got to understand that this isn’t a military weapon. It is used to wipe out women and children and unarmed people, and not for military uses. So we have got to treat this thing differently from rifles and cannons and ordinary things like that.
In one sense, the world has followed Truman in lockstep. A big reason why no one has dropped or fired a nuclear weapon in wartime in the 80 years since Nagasaki—a remarkable fact that almost no one would have thought possible at the time—is the fear of its consequences, aka Mutually Assured Destruction: If you blow us to smithereens, we’ll blow you to smithereens.
Yet in another sense, in the decades since, military officers and civilian strategists have tried to work around Truman’s warning—have tried to figure out how to turn the bomb into “a military weapon.” In the early days of the Nuclear Age, the top generals, like Curtis LeMay, the first head of the Strategic Air Command, did so with a ruthless attitude: War was about killing people and destroying countries, so the bigger the bomb, the better. However, later on, some strategists thought about how to fight a nuclear war because they calculated doing so was the best way to deter such a war from happening.
Then, in the late 1950s and early ’60s, the Soviets started fielding their own nuclear bombers and missiles. Suddenly, America’s policy—which President Dwight Eisenhower called “massive retaliation”—seemed like a prescription for suicide. If the Soviets invaded Western Europe and we responded by blowing up Moscow and other major cities, then the Soviets would strike back by blowing up our own cities.
As a result of this logic, our policy just as suddenly lost credibility. Would we commit national suicide? Or, as French President Charles de Gaulle put it, would an American president risk Washington for Paris? De Gaulle thought not, and he started building his own nuclear arsenal—so he wouldn’t have to rely on American sacrifice in order to deter a Soviet attack. (Great Britain also built some nuclear weapons, but its policy on how to use them was kept within NATO’s military framework and coordinated with Washington. De Gaulle left NATO’s military command structure.)