U.S. Secretary of State John Kerry speaks during a news conference at the London Conference on Afghanistan, in London December 4, 2014. The U.S. and Britain pledged on Thursday to support Afghanistan's new unity government even as foreign combat troops withdraw from the country after a 13-year war that ousted the Islamist Taliban. REUTERS/Alastair Grant/Pool (BRITAIN - Tags: POLITICS MILITARY CIVIL UNREST)