I've just finished The Fog of War: Eleven Lessons from the Life of Robert S. McNamara. It is a powerful message about war and the people that lead us.
McNamara was in the Air Force during WWII, then the president of Ford, then the Secretary of Defense during some of the darkest days of the cold war, and the beginning of the Vietnam war. He talks about some of the decisions he was involved with, including the firebombing of Tokyo, and the use of Agent Orange; the defense of the indefensible, acts that today would be considered criminal. The film does humanize in some ways a man who was condemned and hated at the time, who tried to do what he considered right. It's well worth watching, a great documentary, with good use of archive footage.
One of his lessons -- talking about the lack of support from our allies in Vietnam -- seems even more relevant now with the war in Iraq:
We are the most powerful nation in the world - economically, politically and militarily - and we are likely to remain so for decades ahead. But we are not omniscient.
If we cannot persuade other nations with similar interests and similar values of the merits of our proposed use of that power, we should not proceed unilaterally except in the unlikely requirement to defend directly the continental U.S., Alaska and Hawaii.
The eleven lessons of McNamara: