Soldiers detect Unexploded Ordnance (UXO) and defoliant Agent Orange during the launch of the "environmental remediation of dioxin contamination" project, in Vietnam's central Da Nang City June 17, 2011. The U.S. and Vietnam launched the first concrete step toward 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. [Photo/Agencies] 

Soldiers detect Unexploded Ordnance (UXO) and defoliant Agent Orange during the launch of the "environmental remediation of dioxin contamination" project, in Vietnam's central Da Nang City June 17, 2011. The U.S. and Vietnam launched the first concrete step toward 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. [Photo/Agencies]