On September 10, Defense Secretary Donald Rumsfeld was a man out of time. Pursuing his madcap missile-defense strategies, proposing to radically downsize and reshape the American military, sending out “blizzards of snowflakes,” as his memos were called, and dreaming of regime change in Iraq, he was either a pest or an irrelevance, depending on where in the chain of command you happened to sit. But the attacks reoriented the arc of his career, giving his iconoclastic ideas a power they wouldn’t have had otherwise. Soon, Special Forces on horseback in ­Afghanistan were calling in bombers to drop massive “daisy-cutters” that killed everything in a three-mile radius. Rumsfeld had displayed conspicuous nervelessness after the plane hit the Pentagon, and before the week was out, he was urging the president not to let the crisis go to waste, to use it as an opportunity to remake the world by ousting Saddam Hussein.

For a while, Rumsfeld was a new man—“a damn fine secretary of war,” said one of his generals who had previously disparaged him. He was also one of the great press-conference artists and bureaucratic poets of all time, speaking of “known unknowns” [R2] and “untidy” freedoms and talking rings around his interlocutors—no doubt, he was one of the smartest, wittiest men in Washington. But the years after 9/11 made some of his ideas seem loopier than they had been before—the failure at Tora Bora gave the lie to his “revolution in military affairs.” And the long slog in Iraq, still not over, put him in the same conversation as Vietnam mastermind Robert ­McNamara, despite Rumsfeld’s assurance that “I don’t do quagmires.” McNamara eventually ­apologized.