The US and its allies have made only patchy progress in the Afghan war, with overall violence declining just slightly in the past year and widespread corruption continuing to hamper a shaky government, according to a new Pentagon report.
It also said ongoing insider attacks, in which Afghan forces or people dressed in Afghan uniforms turn their weapons on coalition troops, "have the potential to significantly disrupt the coalition mission in Afghanistan".
The report comes as the US Army is updating its handbook for soldiers on how to detect and prevent such attacks. A draft of the 70-page handbook includes a pullout tip card that details indicators of a possible insider attack, such as reclusive behaviour, desire for control, increased focus on violence and abrupt behavioural changes.
It also reminds soldiers to be aware of cultural differences, including the need to avoid doing things in front of Afghans that are considered offensive. Troops should not blow their noses, put their feet up on desks, wink, spit, point fingers at Afghans or use the "okay" hand signal, which some Afghans interpret as an obscene gesture,
The handbook - titled Insider Threats - Afghanistan, Observations, insights and Lessons Learned - also details the more than 320 casualties caused by insider attacks between May 2007 and October 1 this year.
A recent review of the data by the Associated Press revealed that the Haqqani insurgent network, based in Pakistan and with ties to al Qaida, is suspected of being a driving force behind a significant number of the insider attacks.
Military leaders have worked to reduce the insider threat, noting that it is driving a wedge between coalition and Afghan troops, rattling the trust between them and raising questions about how effectively the allied forces can train the Afghans to take over security of their own country in 2014 and beyond.
Senior officials acknowledge that the US continues to be very concerned about the attacks, even though there have been fewer in recent months. The coalition forces are trying to identify high-risk groups, and the handbook is aimed at helping them do that.
At least 63 coalition troops - mostly Americans - have been killed and more than 85 wounded in at least 46 insider attacks so far this year. That is an average of nearly one attack a week. Last year, 21 insider attacks killed 35.
At the same time, Taliban leaders are calling on insurgents to battle on through the coming winter season to try to take back ground they have lost, but a senior defence official said the US has seen no increased effort on the part of the fighters. The report shows that the number of enemy attacks for the first nine months of the year dipped by about 3% compared to the same time frame last year, but the level of violence was higher this year than it was in 2009.