On May 22, 1964, National Security Adviser McGeorge Bundy sent a memo to President Johnson. "An integrated political-military plan for graduated action against North Vietnam is being prepared under John McNaughton at Defense," he wrote. "The theory of this plan is that we should strike to hurt but not to destroy, and strike for the purpose of changing the North Vietnamese decision on intervention in the south." Two days later, Bundy sent a follow-on note recommending that the United States "use selected and carefully graduated military force against North Vietnam," that troops be deployed "on a very large scale, from the beginning, so as to maximize their deterrent impact and their menace. A pound of threat is worth an ounce of action—as long as we are not bluffing."
In an interview 25 years ago for a book that I was writing about the nuclear strategists, Schelling told me what happened next. McNaughton came to see him. He outlined the administration's interest in escalating the conflict in order to intimidate the North Vietnamese. Air power seemed the logical instrument, but what sort of bombing campaign did Schelling think would best ensure that the North would pick up on the signals and respond accordingly? More broadly, what should the United States want the North to do or stop doing; how would bombing convince them to obey; how would we know that they had obeyed; and how could we ensure that they wouldn't simply resume after the bombing had ceased?
Schelling and McNaughton pondered the problem for more than an hour. In the end, they failed to come up with a single plausible answer to these most basic questions. So assured when writing about sending signals with force and inflicting pain to make an opponent behave, Tom Schelling, when faced with a real-life war, was stumped.
He did leave McNaughton with one piece of advice: Whatever kind of bombing campaign you end up launching, it shouldn't last more than three weeks. It will either succeed by then—or it will never succeed.
The bombing campaign—called Operation Rolling Thunder—commenced on March 2, 1965. It didn't alter the behavior of the North Vietnamese or Viet Cong in the slightest. Either they didn't read the signals—or the signals had no effect.
On March 24, almost three weeks to the day after Rolling Thunder began, McNaughton—again following Schelling's lesson—sent the first of several pessimistic memos to McNamara: "The situation in Vietnam is bad and deteriorating." Our aim at this point, he wrote, should be merely to "avoid a humiliating U.S. defeat." Keep up the pressure to affect the North's "will" and to provide the U.S. with "a bargaining counter" so that we "emerge as a 'good doctor.' We must have kept promises, been tough, taken risks, gotten bloodied and hurt the enemy very badly." But victory was not in the cards, and we should seek a way out.
The bombing escalated. When that didn't work, more troops were sent in, a half-million at their peak. The war continued for another decade, killing 50,000 Americans and untold numbers of Vietnamese. McNamara grew increasingly disillusioned but kept up the pretense of a light at the end of the tunnel. In the spring of 1967, John McNaughton died in a plane crash.* In November of that year, McNamara, exhausted and in despair, resigned—or he was fired, it's never been clear which—and went to wring his bloodied hands in the World Bank's fountains.
Tom Schelling didn't write much about war after that. He'd learned the limitations of his craft. If Donald Rumsfeld and Paul Wolfowitz had studied history better, they, too, might have appreciated those limits before chasing their delusional dreams into the wilds of Mesopotamia.
Correction, Oct. 12, 2005: John McNaughton died in a plane crash, not a helicopter crash as this article originally and incorrectly stated.