I do not minimize Al Qaeda’s intentions, which are barbaric. I question its capabilities. In every recent conflict, the United States has been right about the evil intentions of its adversaries but massively exaggerated their strength. In the 1980s, we thought the Soviet Union was expanding its power and influence when it was on the verge of economic and political bankruptcy. In the 1990s, we were certain that Saddam Hussein had a nuclear arsenal. In fact, his factories could barely make soap…

Some 30,000 people are now employed exclusively to listen in on phone conversations and other communications in the United States. And yet no one in Army intelligence noticed that Maj. Nidal Malik Hasan had been making a series of strange threats at the Walter Reed Army Medical Center, where he trained. The father of the Nigerian “Christmas bomber” reported his son’s radicalism to the U.S. Embassy. But that message never made its way to the right people in this vast security apparatus. The plot was foiled only by the bomber’s own incompetence and some alert passengers.

Such mistakes might be excusable. But the rise of this national-security state has entailed a vast expansion in the government’s powers that now touches every aspect of American life, even when seemingly unrelated to terrorism.