One of the largest obstacles to peace discussions has been widespread Afghan contempt for U.S. military tactics often criticized as heavy-handed. Opposition to the U.S. and NATO military presence in Afghanistan usually centers on civilian casualties from military engagement, although the vast majority of those deaths are caused by the insurgents.
Although the urination video purports to show Taliban fighters, not civilians, it is likely to resonate with those opposed to the U.S. presence and to peace with the U.S.-backed Karzai government.
U.S. officials seemed to have ordered a variety of investigations:
--Panetta said he had ordered the Marine Corps and Marine Gen. John Allen, the top commander of the NATO-led forces in Afghanistan, to fully investigate.
--In a written statement, the commandant of the Marine Corps, Gen. James Amos, said he requested on Wednesday evening that the Naval Criminal Investigative Service investigate, and that the Marines would, separately, do their own internal investigation.
"The Marine Corps will not rest until the allegations and the events surrounding them have been resolved. We remain fully committed to upholding the Geneva Convention, the Laws of War, and our own core values," Amos said.
The NATO-led security force in Afghanistan released a statement Thursday saying, "This disrespectful act is inexplicable and not in keeping with the high moral standards we expect of coalition forces."
The actions "appear to have been conducted by a small group of U.S. individuals, who apparently are no longer serving in Afghanistan," the International Security Assistance Force said. The statement did not identify the personnel or explain why the ISAF thought they had left the country.
A spokesman at Camp Lejeune in North Carolina would not confirm reports that the Marines were based there. "We have had elements of that unit that have deployed to Afghanistan and have returned. However, we have not yet confirmed if anyone in the video is from that unit, or whether they are attached to a unit from Lejeune," said Capt. Scott Sasser.
Pentagon officials said the criminal investigation would likely look into whether the Marines violated laws of war, which include prohibitions against photographing bodies and detainees and a range of other rules.
Mujahid urged the U.N. and other international groups to end such actions by U.S. troops.
On Wednesday, the Council on Islamic-American Relations, a prominent Muslim civil rights and advocacy group based in Washington, protested the video in a letter to Panetta.
"We condemn this apparent desecration of the dead as a violation of our nation's military regulations and of international laws of war prohibiting such disgusting and immoral actions," the group wrote.
"If verified as authentic, the video shows behavior that is totally unbecoming of American military personnel and that could ultimately endanger other soldiers and civilians," the letter said.