Wars:
Afghanistan was being used as the major base for Al Qaeda, which was supported by the most powerful faction in the country, the Taliban. Invading Afghanistan made sense, it was terrorism central, and the location of much of the Al Qaeda leadership, including Osama Bin Laden.
Invading Iraq was basically a policy decision on the Bush administration's part with the naive goal of creating a friendly democracy in the middle east. Saddam was a brutal dictator, despised by his own people. All you would have to do is defeat the Saddam regime, the people would exchange hearty high fives with your "liberating" soldiers, and you'd have an instant buddy with a reliable oil supply. Or so was the thinking... no one in the administration realized that Saddam was actually holding together the country against sharp sectarian divides that were exacerbated by the recent upswing in violent Islamic extremism- and BOOM, we're in a civil war.
Please note that WMD was essentially a flimsy excuse for the invasion.
As for the crew I think it would be too easy for us to assume that we wouldn't be acting in a similar way if we had the same background. Living in fear for your life, or fear for the life of your fellow soldiers is a powerful force. Combined with the desensitization and addiction to violence and the accompanying adrenaline that often happens to soldiers, you get this kind of (to us) alien culture.
It's been the mistake of every generation to think that they're somehow immune to the drug of war. Go read
War is a Force that Gives Us Meaning.
Of course, people like to get upset and feel self-righteous about stuff like this and tend to forget that there was a time when we
deliberately targeted civilians. Considering this as a war crime, it pales in comparison to
My Lai, where those children would have been finished off point-blank, not taken to a hospital.
