Soldiers from the 3rd Brigade, 1st Cavalry Division bow their heads in prayer during a casing of the colors ceremony while preparing to depart from Iraq at Camp Adder, now known as Imam Ali Base, near Nasiriyah, Iraq on December 17, 2011. The last convoy of U.S. soldiers pulled out of Iraq on Sunday, ending their withdrawal after nearly nine years of war and military intervention that cost almost 4,500 American and tens of thousands of Iraqi lives. Picture taken December 17, 2011. REUTERS/Mario Tama/Pool (IRAQ – Tags: CONFLICT MILITARY POLITICS)