John Mueller is senior fellow at the Cato Institute and professor of political science at Ohio State University. He is the author of Atomic Obsession: Nuclear Alarmism from Hiroshima to Al-Qaeda; together with Mark Stewart, he wrote Terror, Security, and Money: Balancing the Risks, Costs, and Benefits of Homeland Security.

Some decades ago, Columbia University’s Warner Schilling observed that "at the summit of foreign policy, one always finds simplicity and spook."

I was reminded of this observation when I came across a passage in George F. Kennan, the excellent Pulitzer Prize-winning biography of the prominent foreign-policy intellectual by John Lewis Gaddis. In 1950, notes Gaddis, no one anticipated most of the major international developments that were to take place in the next half-century, among them "that there would be no World War" and that the United States and the USSR, "soon to have tens of thousands of thermonuclear weapons pointed at one another, would agree tacitly never to use any of them."

But the absence of further world war, whether nuclear or not, was compatible with a fairly obvious observation: those running world affairs after World War II were the same people or the intellectual heirs of the people who had tried desperately to prevent that cataclysm. It was entirely plausible that such people, despite their huge differences on many issues, would manage to avoid plunging into a self-destructive repeat performance.

Thus, it could have been reasonably argued at the time that major war was simply not in the cards...