The movie begins with a quote from the book War is a Force that Gives Us Meaning
"The rush of battle is often a potent and lethal addiction, for war is a drug."The movie does a good job communicating this idea.
My main impressions were:
1. The contrasting power of the Americans and the Iraqi citizens.
2. The clear estrangement between the two.
3. The hopelessness of the situation, for both parties.
4. War is hell, i.e. it is all about sin, violence, death, fear, ..... There is nothing glorious about it.