Associated Press
Secretary of State Hillary Rodham Clinton expresses her dismay at emerging reports of U.S. Marines allegedly desecrating the bodies of Taliban fighters killed in Afghanistan, Thursday, Jan. 12, 2012.
When you ask young men to go kill people for a living, it takes a whole lot of effort to rein that in. —Reserve Marine Lt. Col. Paul Hackett

Since before Achilles dragged Hector's body around the walls of Troy, warriors have been desecrating the corpses of their vanquished enemies, whether to send a message or exact revenge.

The video that surfaced this week of four Marines apparently urinating on three Taliban corpses has stirred outrage in the U.S. and beyond, but also focused attention on the brutalizing effects of war on those sent to wage it.

Reserve Marine Lt. Col. Paul Hackett, who teaches the law of war to Marines before they are sent off to Afghanistan, made it clear Friday that he was not condoning the Marines' actions. But he warned against judging them too harshly, saying: "When you ask young men to go kill people for a living, it takes a whole lot of effort to rein that in."

In the long history of war, the episode pales in comparison to other battlefield atrocities. But one difference this time was that, in the Internet age, it was captured on camera and instantly shared with the rest of the world.

"This outrage is so interesting to me because it almost tops that" of other, more ghastly war crimes, said psychologist Eric Zillmer, a Drexel University professor and co-editor of the book "Military Psychology: Clinical and Operational Applications." "Because of the technology, the video, you actually see it. Most of the other war crimes, you heard about, you read about."

The Geneva Conventions forbid the desecration of the dead, and officials in the U.S. and abroad have called for swift punishment for the four Marines, identified as members of the 3rd Battalion, 2nd Marines, which fought in the Afghan province of Helmand for seven months before returning to Camp Lejeune, N.C.

In Jacksonville, N.C., the home of Camp Lejeune, some people resented criticism of the Marines over the video, and some expressed fear the footage would make their job harder.

"It demolished me to see that," said Arthur Wade, a Vietnam veteran who retired in 1989. "If one of those men being urinated on was your father, would you want to help the United States?"