Sean Smith in Iraq May 2007

American marines from 1st Battalion, 3rd Marine Division, eating in their combat outpost in al-Anbar province, Iraq Photograph: Sean Smith/Guardian

American soldiers from Charlie Company, 2nd Brigade, 10th Mountain Division, at a watch tower near COP Corregidor, not far from Yusifiyah in the 'triangle of death' in Iraq Photograph: Sean Smith/Guardian

An American marine from 1st Battalion, 3rd Marine Division, on patrol in a residential district of al-Anbar province, Iraq Photograph: Sean Smith/Guardian

American marines from 1st Battalion, 3rd Marine Division, with blindfolded and handcuffed detainees about to be released in al-Anbar province, Iraq Photograph: Sean Smith/Guardian

American soldiers from Charlie company, 2nd Brigade combat team, 10 mountain division on a foot patrol in the so-called 'triangle of Death' near COP Corregidor not far from Yuossifiah, south of Baghdad, Iraq. Two soldiers have been lost to IEDs in the last month during foot patrols.They took shelter in the small farm after mortars were fired in their direction Photograph: Sean Smith/Guardian

American soldiers from Bravo Company, 2nd Brigade combat team, 10th Mountain Division, search a house near Yusifiyah in the 'triangle of death' in Iraq after an IED exploded on the road near a vehicle patrol Photograph: Sean Smith/Guardian

: American soldiers from Bravo Company, 2nd Brigade combat team, 10th Mountain Division, with two of three men detained after an IED exploded on the road near a vehicle patrol. All three tested positive for explosives in a basic hand-swab test. A second IED failed to detonate near Yusifiyah in the 'triangle of death' in Iraq Photograph: Sean Smith/Guardian

American soldiers from the mortar team of 2nd Brigade combat team, 10th Mountain Division, return fire near Yusifiyah in the 'triangle of death', Iraq Photograph: Sean Smith/Guardian

American soldiers from Alpha Company, 2nd Brigade combat team, 10th Mountain Division, during a sweep with the Iraqi army near Yusifiyah in the 'triangle of death', IraqAmerican soldiers from Alpha Company, 2nd Brigade combat team, 10th Mountain Division, during a sweep with the Iraqi army near Yusifiyah in the 'triangle of death', Iraq Photograph: Sean Smith/Guardian

American soldiers from Charlie Company, 2nd Brigade combat team, 10th Mountain Division in a watch tower near COP Corregidor, not far from Yusifiyah in the 'triangle of death', Iraq Photograph: Sean Smith/Guardian