It is said that Hermann Goering complained to the Nuremburg tribunal that they were on trial because they lost the war. And the answer was that they were not on trial because they lost the war, but because they started it.
after five years of war, it seems that no real lesson has been learned. Indeed, there's a refusal to even acknowledge why it was wrong to invade Iraq.
And Goering's is the lesson that many US supporters of the Iraqi-American War have failed to learn. They like to talk about "appeasement", but forget that in the 1930s the ones who were being appeased were the aggressors. In the case of the Iraqi-American War the appeasers were people like Tony Blair, who appeased George Bush, and did not stand up to his plans for aggression.
And Hillary Clinton apparently went along with her husband's bombing of Yugoslavia.