"Upon taking office, the Obama Administration faced a deteriorating security environment in Afghanistan, despite a steady increase in U.S. forces there in recent years. Signs of deterioration included an expanded area and greater intensity of militant operations, higher levels of overall violence, Afghan and international disillusionment with corruption in the government of Afghan President Hamid Karzai, and the ease of infiltration of Taliban militants from safe havens in Pakistan. Building on assessments completed in the latter days of the Bush Administration, the Obama Administration has conducted two 'strategy reviews' the results of which were announced on March 27, 2009, and on December 1, 2009, respectively. The outcome of both reviews was to add combat troops but with the intent of creating safe conditions to expand Afghan governance and economic development. As part of the early 2009 review, the President announced an increase of 21,000 U.S. troops, which arrived by November 2009 and brought U.S. force levels to about 68,000, in partnership with about 39,000 international forces from 43 other nations, and about nearly 200,000 Afghan security forces."
CRS Report for Congress, RL30588