While authorities in Afghanistan investigate whether last weekend's firefight that killed two Americans and three Afghan soldiers was another insider attack, observers fear the threat of Afghans turning their guns on their allies may have already become ingrained in the minds of coalition soldiers.
"The fact of the matter is people are now worrying what's happening behind our back, not what's happening in front of them, especially when we transition to a train-and-assist mission," said Michael Ruben, a resident scholar at the American Enterprise Institute in Washington who trains troops deploying to Afghanistan. "This is pretty much 95 percent of what soldiers worry about now."
NATO's International Security Assistance Force said Saturday's attack at a checkpoint near an Afghan National Army unit in Wardak province possibly involved gunfire from insurgents but was initially suspected as an insider attack, also known as "green-on-blue" incidents.
Gunfire broke out "after a short conversation" between personnel from the two forces, according to an ISAF statement. But there appear to be conflicting reports between Western and Afghan officials. A provincial spokesman, Shahidullah Shahid, told The Associated Press that an American unit believed it was being attacked by a nearby Afghan checkpoint and returned fire, which led to the Afghans firing back at the U.S.
NATO and the Afghan army are investigating the incident.
Malou Innocent, a foreign policy analyst at the Cato Institute in Washington, said the incident "reflects the deepening mistrust between the coalition and their Afghan counterparts."
She added that the incident exemplifies the "poor communication" between coalition and Afghan forces.
In the more than 30 attacks Afghan government troops have carried out on NATO forces this year, 51 service members, mostly Americans, have died, more than the last two years combined, CBS News national security correspondent David Martin reports.
U.S. and NATO forcesjoint field operations with the Afghans last month because they became such a problem, Martin reported.
Just last week, Defense Secretary Leon Panetta said the joint operationsalthough the reasoning behind the suspension appeared to have changed.
On Wednesday, ISAF Deputy Commander Adrian Bradshaw, a British lieutenant general, told reporters that the suspension was related to the violent protests stemming from an American-made online video ridiculing the Muslim Prophet Muhammad. Bradshaw also insisted that insider attacks accounted for 4 percent of the war's total casualties, even as reporters pointed out that they represent one-fifth of casualties from this year.
His attempt to downplay the effect of the attacks contrasted with recent comments by NATO Secretary-General Anders Fogh Rasmussen, who acknowledged the strain they've put on international troops, CBS Radio News reporter Teri Schultz reports.
"No doubt insider attacks have undermined trust and confidence, absolutely," Fogh Rasmussen said Monday.
Outside Combat Outpost Little Blue, north of Kandahar, Afghanistan, Army Staff Sgt. Stephen Christopher Whitfield told CBS News correspondent Charlie D'Agata that he was concerned having his base right next to another base manned by armed Afghan forces.
"Of course it does, with the insider threats that are taking place in the last couple of months," said Whitfield, "but you deal with whatever situation you have, and we've never had a problem out here."
Innocent said recent controversies such as the online video showing U.S. soldiers urinating on dead Taliban fighters and the burning of copies of the Muslim holy book, the Koran, at a military base created the perception of a lack of respect for Afghan cultural values.
"This is a sort of a confluence of the factors that created this incident," Innocent said.
Ruben, however, said the attacks go much deeper than a sense of disrespect.
"The notion that green-on-blue violence is basically the result of personal problems between Afghan troops and their American partners is nonsense, but the Pentagon doesn't want to consider the alternative," he said.
That alternative embraced by Ruben, a former Pentagon official who's now a senior lecturer at the Naval Postgraduate School, is that the attacks are ideologically inspired, noting that the attackers aren't just killing international troops but are also turning their guns on fighters in the Afghan army.
"It can't be solved by being more polite with Afghan colleagues," Ruben said.
In fact, a Taliban commander told CBS News chief foreign correspondent Lara Logan in an interview broadcast on CBS' "60 Minutes" Sunday that insider attacks "part of our new military strategy" and "the orders come from the top."
Al Qaeda fighters have been coming into Afghanistan to work on the attacks with the Taliban, said the commander, who spoke to Logan on condition of anonymity. He told her that more than a dozen Qaeda militants operate under his command.
Ruben wouldn't say whether Saturday's incident would have happened if Western soldiers didn't feel threatened by insider attacks.
"All I can say," he said, "is it certainly is going to lead to some itchy trigger fingers."