There is a particular danger with a war that God commands. What if God should lose? That is unthinkable to the evangelicals. They cannot accept the idea of second-guessing God, and he was the one who led them into war. Thus, in 2006, when two thirds of the American people told pollsters that the war in Iraq was a mistake, the third of those still standing behind it were mainly evangelicals (who make up about one third of the population). It was a faith-based certitude.
(via Howie Klein)