Lehrer has just asked the candidates what they regard as the lessons of Iraq.

McCain: We can't go to war without enough troops. The consequences of defeat would have been a wider war, sectarian violence and continued conflict. Instead, because of his (McCain's) push for a new strategy, the surge worked, and we're coming home as victors.

Obama: We shouldn't have gone into this war to begin with. We had no idea what it would cost, what the exit strategy would be, how our decision to invade would effect our relations with other nations. And the war in Afghanistan wan't finished. "We have to use our military wisely, and we did not use our military wisely with Iraq."