"At the end of 2014, the United States and partner countries completed a transition to a smaller mission consisting primarily of training and advising the Afghanistan National Defense and Security Forces (ANDSF). The number of U.S. forces in Afghanistan, which peaked at about 100,000 in June 2011, stands at about 9,800, of which about 1,000 continue to conduct combat under U.S. 'Operation Freedom's Sentinel' that replaced the post-September 11 'Operation Enduring Freedom.' U.S. forces constitute the bulk of the 13,000-person NATO-led 'Resolute Support Mission.' Amid assessments that the ANDSF is having difficulty preventing gains by the Taliban and other militant groups (exemplified by the insurgent overrunning of the northern city of city of Konduz in late September 2015) President Obama announced on October 15, 2015, that about 10,000 U.S. military personnel would remain in Afghanistan through almost all of 2016, and subsequently fall to 5,500. The 5,500 person post-2016 force is significantly larger than the U.S. force of about 1,000 personnel that was previously announced for that timeframe. Prior to the Konduz takeover, U.S. officials asserted that insurgents did not pose a threat to the stability of the government, and U.S. officials have not subsequently altered that assessment publicly. The insurgency benefits, in some measure, from weak governance in Afghanistan. A dispute over the 2014 presidential election in Afghanistan was settled in September 2014 by a U.S.-brokered solution under which Ashraf Ghani became President and Dr. Abdullah Abdullah was appointed to a new position of Chief Executive Officer of the government."
CRS Report for Congress, RL30588
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html