Three Iraq combat veterans from Colorado have launched themselves on a new kind of mission abroad: fighting poverty as civilians. Discharged this year from the Quebec Battery, 5th Battalion, 14th Regiment of the 4th Marine Division, a reserve unit based at Buckley Air Force Base, the three are devoting themselves to humanitarian aid projects in Asia and Africa. A fourth is setting up a domestic violence support service he will pursue when he leaves the Marine Corps. “After you’ve experienced the world at its worst, it seems to be a natural instinct to want to make it better,” said Cpl. Brenton Hutson, 24, a Wheat Ridge High School graduate who joined the military at age 17 and served in Ramadi and Fallujah in 2006 during the worst of Iraq’s sectarian war. National veterans group leaders say the jump from combat to humanitarian aid is becoming common as Americans return from war and want more than a comfortable domestic existence.