The second part of this damning examination of the decision to invade Iraq and the years of war and destruction that followed.
When Lieutenant Colonel Nate Sassaman (pictured) arrived in Iraq in 2003, his belief in the task ahead – of delivering democracy and stability to the Iraqi people – was unquestioning.
Sassaman was an inspirational leader to his men, and many felt that he was destined one day to become a general. Six months into his tour, caught in the political and literal cross fire of the insurgency, his good intentions and belief systems were shattered. Unprepared for the hostile environment he found himself in, with little support coming from Washington and taking daily attacks from insurgents, Sassaman was pushed to the very darkest regions of his psyche.
Alaa Adel was 12 years old in the summer of 2003, when she too was caught in cross fire on the streets of Baghdad. She suffered life changing injuries when she was hit in the face by shrapnel from one of the first roadside bombs, planted by insurgents and intended for American forces.
Looking back at that time, both Sassamen and Alla question the benefits of the war in Iraq. While one struggles with the guilt of their actions, the other lives with bristling resentment and ongoing anger.
Once Upon a Time in Iraq – Monday at 9.00pm on BBC One.