Civilian casualties allegedly caused by errant United States fire may be opening a serious rift between the new government of Afghanistan and its US protector.
Tuesday, Afghan President Hamid Karzai called US officials into his office to express "grave concern" over the latest reports of such friendly fire casualties. It was the first such strong rebuke since the US campaign against the Taliban and Al Qaeda began.
It isn't yet clear whether US action was indeed responsible for deaths and injuries incurred at a wedding party in southern Afghanistan on Monday. Like so many such incidents, initial details are sketchy, with key aspects disputed by the Pentagon.
But whatever the viewpoint of Washington, officials in Kabul appear to be confronting an increased uneasiness among some Afghan factions about the scale and scope of continued US military operations in their country.
"The main thing about [the latest reported incident] is that it undermines Hamid Karzai. He is already seen as weak and overly reliant on Americans," says Barnett Rubin, director of studies at the Center on International Cooperation at New York University, and a noted expert on Afghanistan.
Afghan officials and local residents claim that dozens of civilians, including women and children, were killed in an early-morning incident in the village of Kakarak, about 175 miles southwest of the capital of Kabul.
Afghan Foreign Minister Abdullah said that as many as four villages were hit by some sort of US firepower during the attack.
Initial reports held that an errant bomb from a US B-52 conducting operations against suspected Taliban or Al Qaeda caves in the area might have been responsible for casualties. But the Pentagon doubts that scenario. A US soldier in the area saw the bomb in question fall into a remote, uninhabited area, according to Defense Department spokesman Navy Lt. Cmdr. Jeff Davis.
Two other possibilities could account for a civilian death toll, said Commander Davis.
A US AC-130 gunship, supporting a separate reconnaissance operation in the area, may have mistakenly fired on villages as it tried to suppress what it believed to be antiaircraft fire. Or, adversary antiaircraft fire could have fallen back to earth and struck people on the ground.
In the past, the US has disputed reports of major casualties caused by US bombing raids. In February, for instance, an unmanned CIA drone unleashed a missile on what the US claims was a group of Al Qaeda fighters. Villagers said that they were local metal scavengers, and that three were killed.
But there have been some undisputed examples of casualties caused by friendly fire. In March, a US fighter attacked a border village in eastern Paktia province, killing 14. The US military has acknowledged that women and children were among them, though it says they were close to an Al Qaeda hideout.
In April, a US F-16 dropped a bomb on Canadian soldiers conducting a night patrol, killing four. An inquiry has recommended disciplinary action be taken against the US pilot.
In general, the US has had a problem with local forces providing erroneous targeting information to settle their own internal scores. "[American commanders'] intelligence is often mistaken, and they do not coordinate well with the Afghan forces," says Barnett Rubin of New York University.
Yet friendly fire incidents are an inevitable part of modern warfare, note other experts.
"Accidents do happen, and sometimes those accidents lead to the loss of innocent lives in a way the US simply didn't intend," says Stephen Walt, a professor of international affairs at the Kennedy School of Government at Harvard.
If such incidents begin to make the US look heavy-handed in Afghanistan, it could interfere with the broader objective of reducing the residual popularity of Osama bin Laden and his remaining followers in the region.
Professor Walt says that is just why in the end, terrorism must be defeated primarily by diplomacy, intelligence, and law enforcement, not repeated applications of American military force.
"Using military force always causes a few negative repercussions that you may not intend, but you also can't avoid," he says. "And this is a perfect case in point."