A Marine has apparently been videotaped shooting an unarmed militant in a mosque:

On the video, as the camera moved into the mosque Saturday, a Marine can be heard shouting obscenities in the background, yelling that one of the men was only pretending to be dead.

"He's (expletive) faking he's dead!"

"Yeah, he's breathing," another Marine is heard saying.

"He's faking he's (expletive) dead!" the first Marine says.

The video then showed a Marine raising his rifle toward an Iraqi lying on the floor of the mosque. The video shown by NBC and provided to the network pool was blacked out at that point and did not show the bullet hitting the man. But a rifle shot could be heard.

"He's dead now," a Marine is heard saying.

The article quotes the Third Geneva Convention:

The Third Geneva Convention, the section of the 1949 treaty that applies to prisoners of war, says "persons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat (out of combat) by sickness, wounds, detention, or any other cause, shall in all circumstances be treated humanely."

But as far as I understand the convention, it doesn't really apply here. The Geneva Convention also says that it applies to combatants that wear clearly marked insignia, of having a clear chain of command, etc.

Clearly this doesn't justify shooting an unarmed person in the head, but what rules are at work here? The story also notes:

The judge advocate general heading the investigation, Lt. Col. Bob Miller, was asked by NBC News whether it was possible the Marine was acting in self-defense.

"The policy of the rules of engagement authorize the Marines to use force when presented with a hostile act or hostile intent," Miller said. "So they would have to be using force in self-defense, yes."

"Any wounded - in this case insurgents - who don't pose a threat would not be considered hostile," said Miller.

Charles Heyman, a senior defense analyst with Jane's Consultancy Group in Britain, defended the Marine's actions, saying the wounded man could have been concealing a firearm or grenade.

"In a combat infantry soldier's training, he is always taught that his enemy is at his most dangerous when he is severely wounded," Heyman said.

If the injured man makes even the slightest move, "in my estimation they would be justified in shooting him."

Okay, so there are experts that disagree on the rules of engagement...how the heck is a grunt supposed to make such distinctions clearly in the middle of conflict?

The story also says:

Sites reported that a Marine in the same unit had been killed a day earlier when he tended to the booby-trapped dead body of an insurgent.

So presumably the unit was wary and jumpy. Again, this doesn't necessarily excuse shooting a wounded, unarmed man, but it seems to me that this may not be a clear-cut case, before any hard conclusions are drawn.

At least we have embedded reporters and a free, widespread press to attempt to make war more transparent.