Whenever troops go off to war, some don't return. About 78,000 Americans who fought in World War II still have not been accounted for; 8,200 are missing from the Korean War.
Yet the far fewer Americans missing in action from the Vietnam War--2,434--have become a much bigger emotional and political issue. In fact, the MIA question has dominated U.S. policy in Southeast Asia since the war ended for the United States in 1973.
"Some people wonder why are we so much concerned," says Col. Howard Hill, the Pentagon's chief adviser on the issue. One reason, he and other officials say, is that the Vietnam War received more intensive and vivid news coverage than any previous American conflict, and generated controversy long after the last troops returned home.
Moreover, excavation and forensic science techniques that did not exist at the end of World War II and the Korean War have raised expectations that America can retrieve and accurately identify physical remains, Hill says.