David Finkel said this quote

It wasn't as if they had a choice. They were soldiers whose choices had ended when they had signed contracts and taken their oaths. Whether they had joined for reasons of patriotism, of romantic notions, to escape a broken home of some sort, or out of economic need, their job now was to follow the orders of other soldiers who were following orders, too. Somewhere, far from Iraq, was where the orders began, but by the time they reached Rustamiyah, the only choice left for a solider was to choose which lucky charm to tuck behind his body armor, or which foot to line up in front of the other, as he went out to follow the order of the day.