With the caveat that I think Bush is doing only one thing right (i.e., his prosecution of the war against Islamo-Fascism), I found this piece from David Gelernter quite refreshing.
THE WAR IN IRAQ is dual-purpose, like most American wars. Take the Civil War. At the beginning, the North fought mainly for pragmatic reasons. No nation can tolerate treason, or allow itself to be ripped to bits or auctioned off piece-wise by malcontents. Midwesterners couldn't allow the Mississippi to fall into foreign hands; they needed their outlet to the sea. And so on. Slavery was overshadowed. But as the war continued, slavery emerged as the issue, and the war's character changed.
The Iraq war started as a fight to knock out a regime that invaded its neighbors, murdered its domestic enemies with poison gas, subsidized terrorism, and flouted the international community. Obviously such a regime was dangerous to American interests. But as the war continued and we confronted Saddam's gruesome tyranny face to face, the moral issue grew more important, as emancipation did in the Civil War. For years the Iraqi people had been screaming, in effect: "Oh, my God. Please help me! Please help me! I'm dying!" How could America have answered, "We don't want to get involved"? We are the biggest kid on the playground. If we won't help, who will?
There's quite a lot; read the whole thing.
Gelernter knows personally about terrorism; a package from the Unabomber blew off his hand.
UPDATE: Forgot the hat-tip to Photon Courier.