PRTs in northern Afghanistan, though several of these will merely replace existing coalition troops.

ECONOMIST: NATO and Afghanistan

PRTs have been a useful improvisation in difficult circumstances, fairly effective in improving security but less so at development work.

ECONOMIST: And now nation-building

PRTs do not have the time or the training for it.

ECONOMIST: And now nation-building

Small units of military and civilian officers, known as provincial reconstruction teams, or PRTs, are to be expanded across Afghanistan, and in particular to provinces along the border with Pakistan.

BBC: NEWS | South Asia | Afghanistan's security nightmare

Aid agencies have often criticised the PRTs, which carry out a mix of reconstruction work, as an inadequate response to deteriorating security - an "Isaf effect" without the means or the mandate.

BBC: NEWS | South Asia | Afghanistan's security nightmare