The decision by Afghanistan’s president, Hamid Karzai, on February 24th to expel American special forces from the province of Wardak, south-west of the capital, Kabul, has thrown the NATO coalition into confusion. It has also turned attention to these elite but shadowy American units. The government has given the forces two weeks to leave the province, accusing them of complicity in murders and disappearances.

The order was announced at a hastily convened press conference, and the crimes were blamed especially on Afghan irregulars who had been recruited to work alongside the Americans. Mr Karzai, however, has made it clear that he holds America responsible. The government says residents of the province have long complained of the irregulars’ abuses and that it is taking action only after the NATO coalition failed to do so.

Mr Karzai’s expulsion of the special forces throws into question a principal element of the coalition’s strategy. These units increasingly play the lead role in fighting the Taliban, as other forces are shifted into training and advising Afghan troops ahead of the full withdrawal of American combat forces by the end of 2014. Both NATO and Afghan commanders credit raids by American special forces for weakening the Taliban.

Special forces are also training tens of thousands of civilians for the Afghan Local Police (ALP), a village-based defence force which has become a central part of the effort to shore up security in rural areas. However many American troops remain in Afghanistan for training after 2014, local commanders are expected to want plenty of special forces alongside them.

Both the raids by special forces and the recruiting of militiamen at the local level have always sat uneasily with Mr Karzai. It was only after much arm-twisting that he was persuaded to accept the idea of the ALP at all. As the deadline nears for the Afghan government to assume all responsibility for the country’s security, the president has wanted to be seen exerting Afghan sovereignty and clearly laying down what NATO can and cannot do in the provinces.

What rankles the government about the allegations in Wardak is the suggestion that the Americans are getting unaccountable Afghans to do their dirty work. Such proxy forces have long existed in Afghanistan and, this time around, date from the earliest stages of the American war, when bags of dollars were handed to local strongmen to buy the services of their militias. At the time, hostility towards the Taliban overrode any unsavoury behaviour. Both American special forces and the CIA have murky histories with such paramilitary groups.

Who stands accused of the crimes in Wardak, and whether there are such American-backed groups there at all, is central to the confusion today. “I genuinely don’t know who is operating there,” says one NATO official. The picture is further muddied because the main Kabul-to-Kandahar highway that runs through Wardak is partly secured by another armed force of Afghans known to be working for private-security companies. Whatever crimes were or were not committed in the province, Mr Karzai’s government blames the Americans for creating “parallel groups and structures” of Afghan forces outside the control of the government.

Local leaders from Wardak confirm the abuses took place, but do not know who committed them. The perpetrators sometimes wore uniforms and sometimes not, say locals, who say the men were not part of the Afghan army.Meanwhile America is holding drawn-out negotiations with Mr Karzai over the role and status of American troops who stay beyond 2014. The Afghan announcement about American special forces in Wardak may have something to do with these talks. In previous rounds of negotiations, NATO has sometimes surprised observers by backing down on points which had seemed non-negotiable only a few years earlier. Mr Karzai may now be pressing them to make similar choices about the use of special forces.

Afghanistan: Yankee beards go home, Economist, Mar. 2, 2013, at 42