Months after the United States invaded Iraq in 2003, I began filming the U.S. Army’s 2nd Battalion, 3rd Field Artillery Regiment (known as the Gunners) in Baghdad. The unit was housed in a bombed-out palace on the banks of the Tigris that they named Gunner Palace. Rather than just making a movie about the men, I suggested that we make a film together — an offer that the soldiers quickly embraced. They told the story of the war as only they could: They played guitar, spat out rhymes and played to the camera. But behind all their bravado and posturing, they were just kids who desperately wanted the world to understand the war through their eyes.