HEROES: The Unknown

In the beginning he was 16 million. He was the U.S. Army and its Air Forces; he was the Navy, the Marines and the Coast Guard, outward bound for battle in World War II. Then he was the 400,000 U.S. dead, and later—as overseas grave-registration teams sifted out fragments of identifications—he was the 8,000 unidentifiable.

By next spring, the Department of Defense announced last week, he would be six. Chosen by lot and code number from among the unidentified dead of each war theater, he would be brought to the U.S. by air and sea in sealed steel, and then secretly...