NEW : Cameron says a WikiLeaks reference to a lack of troops in the past is trueAfghan president WikiLeaks expresses his gratitude for Afghanistan 's support . `` Britain has contributed in the sacrifice of its soldiers , of blood and of resources in Afghanistan for which the Afghan people are extremely grateful . U.S. Marines troops could start heading home by the end of 2011 . Cameron 's goal is to turn over security operations in Afghanistan before the end of 2011 .
NEW : Cameron says a WikiLeaks reference to a lack of troops in the past is trueAfghan president WikiLeaks expresses his gratitude for Afghanistan 's support . U.S. Marines troops could start heading home by the end of 2011 . Cameron 's goal is to turn over security operations in Afghanistan before the end of 2011 .