Paul Krugman's latest column is rather good. An excerpt:

The best book I've read about America after 9/11 isn't about either America or 9/11. It's "War Is a Force That Gives Us Meaning," an essay on the psychology of war by Chris Hedges, a veteran war correspondent. Better than any poll analysis or focus group, it explains why President Bush, despite policy failures at home and abroad, is ahead in the polls.

War, Mr. Hedges says, plays to some fundamental urges. "Lurking beneath the surface of every society, including ours," he says, "is the passionate yearning for a nationalist cause that exalts us, the kind that war alone is able to deliver." When war psychology takes hold, the public believes, temporarily, in a "mythic reality" in which our nation is purely good, our enemies are purely evil, and anyone who isn't our ally is our enemy.

This state of mind works greatly to the benefit of those in power.

One striking part of the book describes Argentina's reaction to the 1982 Falklands war. Gen. Leopoldo Galtieri, the leader of the country's military junta, cynically launched that war to distract the public from the failure of his economic policies. It worked: "The junta, which had been on the verge of collapse" just before the war, "instantly became the saviors of the country."

The point is that once war psychology takes hold, the public desperately wants to believe in its leadership, and ascribes heroic qualities to even the least deserving ruler. National adulation for the junta ended only after a humiliating military defeat.

George W. Bush isn't General Galtieri: America really was attacked on 9/11, and any president would have followed up with a counterstrike against the Taliban. Yet the Bush administration, like the Argentine junta, derived enormous political benefit from the impulse of a nation at war to rally around its leader.

Another president might have refrained from exploiting that surge of support for partisan gain; Mr. Bush didn't.

And his administration has sought to perpetuate the war psychology that makes such exploitation possible.

Step by step, the fight against Al Qaeda became a universal "war on terror," then a confrontation with the "axis of evil," then a war against all evil everywhere. Nobody knows where it all ends.

What is clear is that whenever political debate turns to Mr. Bush's actual record in office, his popularity sinks. Only by doing whatever it takes to change the subject to the war on terror - not to what he's actually doing about terrorist threats, but to his "leadership," whatever that means - can he get a bump in the polls.