Washington ? Under a bright Afghan moon, eight U.S. paratroopers trudged along a ridge in the Korengal Valley, unaware they were walking right into a trap. Less than 20 feet away, a band of Taliban fighters executed the ambush plan perfectly, enveloping the paratrooper squad in an explosion of bullets and grenades.

Army Spec. Salvatore Giunta, a 22-year-old from Hiawatha, Iowa, was knocked flat by the gunfire; luckily, a well-aimed round failed to penetrate his armored chest plate. As the paratroopers tried to gather their senses and scramble for a shred of cover, Giunta reacted instinctively, running straight into the teeth of the ambush to aid three wounded soldiers, one by one, who had been separated from the others.

Two paratroopers died in the Oct. 25, 2007, attack, and most of the others sustained serious wounds. But the toll would have been far higher if not for the bravery of Giunta, according to members of his unit and Army officials.

On Friday, the White House announced that President Obama decided to award Giunta, now a sergeant, the Medal of Honor.

He will become the first living recipient of the Medal of Honor who has served in any war since Vietnam.

Six medals have been awarded posthumously to those who have served in Iraq and Afghanistan, a small fraction of those given during previous conflicts. In comparison, 246 Medals of Honor have been granted to those who fought in Vietnam, 133 for the Korean War and 464 for World War II.

Defense Department officials say the criteria for the medal have not changed. But veterans groups, lawmakers and even some high-ranking military officials have questioned the official explanations. The relative lack of medals from Iraq and Afghanistan, they argue, has contributed to a lack of public appreciation of the sacrifices made by U.S. troops during the last nine years of war.

“The whole thing is very political in the end, that’s one of the sad things about it,” said Joseph A. Kinney, an author and Vietnam veteran who has testified before Congress about the paucity of medals. “I think they just decided they were going to avoid awards of that nature” for Iraq and Vietnam.

Giunta, now 25, is still serving in the Army, as a staff sergeant based in Italy with Battle Company of the 173rd Airborne Brigade. He and his family did not respond to requests for comment for this story. Medal nominees are often counseled by military officials to maintain their silence while their cases pass through multiple levels of review, which can take years. Officials at the Pentagon and White House declined to comment.