From a New York Magazine article regarding Manning.
Manning shipped out to Iraq with a top security clearance, his multiple identities held close inside him. There was abundant evidence that Manning was having trouble keeping it together psychologically, but the Army brushed aside doubts—it desperately needed intel analysts with Manning’s computer skills. After all, the Army was wired; in fact, the whole government had never been more networked, a development that had been pushed partly by the desire to improve information-sharing and shorten reaction time after 9/11. Much of the war was fought remotely; triggers were pulled by people in Langley, Virginia, or outside Las Vegas or field offices near Baghdad, where Manning was eventually posted. Military engagement had turned into a video game—but with real bullets. Manning was built for this sort of combat. In the modern Army, Manning’s skill set made him a highly useful soldier, and a dangerous one.The entire New York Magazine article is available here.
In Iraq, the torments Manning suffered at the hands of his fellow soldiers, his loneliness and concern over his gender, and the hours and hours he would spend in the airless intel office watching the brutal inner workings of the war bore down on him. He was unmoored in a way he hadn’t been before: angrier, less afraid, more certain of what was good and what was evil, and more compelled to act on this dawning righteousness. It was while in Iraq that Manning came across WikiLeaks founder Julian Assange—a charismatic authority figure who, far from rejecting him, as had so many others, took a passionate interest in him and what he had to contribute. Manning had an awakening—and he became, says the U.S. government, a traitor.