I seem to recall that it is actually the Americans that are most often criticized for friendly fire incidents.
Such as 2002 when 2 US aircraft fired on a Canadian platoon
2003 when 3 UK soldiers were wounded by a A-10 Thunderbolt aircraft.
Or last year when an Italian special forces team was fired on whilst freeing a journalist in Baghdad - killing one.
That makes the quote about the accordian rather ironic coming from the Americans don't you think?
As for pulling out of Afghanistan now, what do you think would happen if we did? How long before it's a rats nest of training camps again?