Soldiers in protective gear detect Unexploded Ordnance (UXO) and defoliant Agent Orange at a presentation during the launch of the "Environmental Remediation of Dioxin Contamination" project at the airport in Vietnam's Da Nang City June 17, 2011. The U.S. and Vietnam launched the first concrete step towards cleaning up contamination from Agent Orange on Friday, in what the top U.S. diplomat in the country said was one of the most significant developments ever in bilateral ties. Agent Orange was a dioxin-laced defoliant sprayed by U.S. troops in the Vietnam War to destroy crops and jungle cover shielding guerrillas. REUTERS/Kham (VIETNAM - Tags: HEALTH POLITICS ENVIRONMENT MILITARY CONFLICT)