Marines and soldiers in Iraq are being wounded and killed on a daily basis, so can that help explain why some Marines may have snapped in the town of Haditha, where 24 civilians, including children, were killed last November after a Marine died in a roadside bomb attack?
Retired Army Gen. William Nash, a senior fellow at the Council on Foreign Relations and an ABC News military consultant, said that although there is no excuse for shooting innocent children, Marines and soldiers are susceptible to snapping if certain terrible conditions are in place.
"The fact of the matter is there's three basic ingredients: There's stress, exhaustion, tiredness, the second factor is fear and the third is discipline," said Nash, the author of "In the Wake of War: Improving U.S. Post-Conflict Capabilities." "All those come together under the leadership umbrella, if you will. And if the leadership is insufficient and stress and fear allow people to break down the necessary discipline, then bad things can happen and it's tragic."
"It's stress, fear, isolation and, in some cases, they're just upset," said Army Brig. Gen. Donald Campbell. "They see their buddies getting blown up on occasion, and they could snap."
Today, the New York Times reported that Marine commanders learned about the incident in Haditha within two days, but did not think it warranted investigation.
Haditha is not the only problem the military is facing. There is also controversy swirling around what may have happened in the town of Ishaqi. Some Iraqis say 11 civilians were killed by U.S. troops. Previously unaired video shot by an AP Television News cameraman at the time appears to show at least five children dead, one will bullet wounds to the head. The military said it conducted an investigation and found that the troops lawfully killed four people when going after high-level terrorists.
Failure of Leadership
"I'm surprised, frankly, that they were so quick to come to a conclusion on that particular incident," Nash said. "As you know, the Iraqi government has reservations on the conclusions. At the same time, it's my understanding that in that fight, some significant insurgent leaders were captured or killed. And as a consequence, the military probably feels the other casualties were incidental to the military operation."
Recently, top Marine General Mike Hagee went to Iraq on a special mission to tell his troops about Marine honor -- something that has been called in to question in light of the recent investigations into unlawful killing of civilians my member of the United States military.
"We are quite proud in the Marine Corps of our core values -- courage, honor and commitment," he said.
Despite the military code of honor, allegations of unlawful action persist.
On Wednesday in Samarra, a pregnant woman named Nahiba Jassim and her cousin, Saliha Hassan, were killed by gunfire when their car entered what the U.S. military called a clearly marked, prohibited area near a checkpoint and observation post manned by coalition forces.
According to the military, the driver of the car ignored signals and commands to stop, so troops fired shots to disable the vehicle.
"I think the investigation will ultimately bring out that information," Nash said. "I think the American people will want accountability for what took place, and accountability for the soldiers and Marines on the ground, accountability of the generals that supervise those folks and ultimately [accountability of] the national command authority. The president and secretary of defense are, in fact, responsible for what the armed forces in the United States do or fail to do."
Frustration at the Pentagon
All the attention on these cases appeared to be irritating the Secretary of Defense, Donald Rumsfeld.
"I can't assure the American people of anything with respect to it," said Rumsfeld who maintained that the investigations have not jeopardized his job. "There's an investigation going on with respect. I'm going to repeat myself for the 15th time. There's an investigation going on."
As a result of the Haditha case, several Marines are expected to face charges -- from dereliction of duty to murder. In the town of Hamandiya, sources familiar with that case say several Marines have confessed to dragging a man out of a house, shooting him and then planting an AK-47 on his body. Several Marines in this case are expected to be charged with murder.
In Ishaqi, an anti-American group in Iraq is distributing a video that accuses U.S. troops of executing 11 civilians. A military investigation concluded the charges "are baseless."
"Allegations that the troops executed a family living in this safe house, and then hid the alleged crimes by directing an air strike, are absolutely false," said Army Maj. Gen. William Caldwell.
In an especially disturbing development for U.S. officials, some of those allegations now come from the Iraqi government, including the prime minister, who said U.S. troops do not respect the Iraqi people and kill them just on suspicion.
This story was originally reported by ABC New's Jonathan Karl.