But the swift investigation into and public statement about the incident also shows how U.S. forces are trying to mitigate the negative public relations effects of such incidents by acknowledging them as quickly as possible.
The U.S. Forces-Afghanistan Public Affairs Office originally said last week that the "precision strike" in Herat province had killed an Islamic insurgent leader and 15 of his men. Ghullam Yahya Akbari, known as the Tajik Taliban, was targeted using "credible reports provided by concerned Afghan citizens," the office said.
But then at the weekend, a new statement acknowledged 13 non-combatants had been among the casualties, and U.S. forces say now they do not know whether Akbari was among the dead.
"Coalition forces could not confirm that (Ghullam) Yahya Akbari was among those killed during the operation," U.S. Forces-Afghanistan spokeswoman Capt. Elizabeth Mathias told United Press International in an e-mail message.
Mathias blamed the civilian deaths -- which, according to local reports, included women and children -- on the militants, who "were in and amongst the civilians, and (Akbari) was believed to be among the non-combatants as well."
She said a team headed by U.S. Gen. Michael Ryan had visited the site of the attack and met with families of the bereaved to offer condolences and make sympathy payments.
"Our experience in Herat confirmed that while we are doing many things correctly, in the interests of the Afghan people and our mission here, we still have improvements to make in our processes, and we will do so," Ryan said.
Defense Secretary Robert Gates and Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, have both called recently for such a new approach by the U.S. military to dealing with incidents in which civilian casualties might have happened, in Mullen's case via a rare newspaper op-ed.
"It doesn't matter how hard we try to avoid hurting the innocent, and we do try very hard," he wrote. "It doesn't even matter if the enemy hides behind civilians. What matters are the death and destruction that result and the expectation that we could have avoided it. In the end, all that matters is that, despite our best efforts, sometimes we take the very lives we are trying to protect."
In congressional testimony earlier this month Gates emphasized it was essential to acknowledge mistakes early on to get out ahead of the story.
"Instead of arguing how many there were or whether there were any, we need to say if there were innocent civilian casualties, then we deeply regret this. And we will make appropriate amends. Then go investigate it. Then find out the facts," he said.
"We need to be out there faster than the Taliban in characterizing these incidents."
Turning around perceptions about civilian casualties is part of the "hearts and minds" campaign that must underpin any counterinsurgency like the one Gen. David Petraeus, author of the U.S. Army's updated doctrine on the topic, now seems determined to wage in Afghanistan.
Beyond the question of perceptions lies the reality of a patchwork of different U.S. and NATO efforts to acknowledge and compensate civilian victims -- the number of whom rose by 40 percent last year, according to U.N. figures.
The Campaign for Innocent Victims in Conflict, which advocates for compensation for the civilian victims of U.S. military operations, published a report last week titled "Losing the People: The Costs and Consequences of Civilian Suffering in Afghanistan."
"Providing specific relief to Afghan victims of conflict is both a strategic and humanitarian imperative," the report said. "The killing of a family member can be an invitation for generational revenge."
The group, established in 2003 by U.S. aid worker Marla Ruzicka, who was killed in Iraq in 2005, argues that flaws and gaps in the patchwork of compensation programs risk losing hearts and minds.
"Anger and resentment over civilian casualties and property loss dominate Afghan views of international forces; the anger is especially strong when no help is provided following harm," the report said.
A poll released earlier this month by the BBC and ABC News backs up that bleak assessment. It found that support for U.S. and international forces had plummeted -- with civilian casualties a key cause.
The number of Afghans who believe U.S. forces have performed well in their country has more than halved since 2005, from 68 percent to 32 percent -- and NATO troops have fared little better. Just 37 percent of Afghans now say most people in their area support NATO's International Security Assistance Force, down from 67 percent in 2006. And 25 percent now say attacks on Western forces can be justified -- nearly double the 13 percent who believed that in 2006.
The survey was carried out by the Afghan Center for Socioeconomic and Opinion Research at the turn of the year. Face-to-face interviews were conducted with a random national sample of 1,534 Afghan adults in all 34 provinces.
The poll found civilian casualties in U.S. and NATO airstrikes were a key factor in declining support. Seventy-seven percent of Afghans said such strikes were not acceptable because the risk to civilians outweighed their value in fighting insurgents. And Afghans do not buy the U.S. military's argument that civilian casualties are the fault of Taliban insurgents because they strike from civilian areas. Forty-one percent of respondents blamed poor targeting by international forces, whereas only 28 percent said insurgents were responsible because they conceal themselves among civilians.