SD,  "Surge" is an incorrect term, from the NY Times:  "General Nicholson told lawmakers that he had a shortfall of a 'few thousand' troops and said more personnel would enable the American military to advise the Afghan military more effectively and at lower levels in the chain of command. The international force assisting the Afghans has about 13,000 troops, of whom about 8,400 are American.  American officials said that 3,000 to 5,000 additional troops, including hundreds of Special Operations forces, could be sent."  https://www.nytimes.com/2017/05/08/us/politics/donald-trump-afghanistan-troops-taliban-stalemate.html

The dilemma of AF, do we completely withdraw and leave AF to its fate or do we find the right mix of hard and soft power to keep the Taliban from power long enough (unknown time) so the AF government can become legitimate enough to counter the Taliban on its own?  AF was the command, control, and planning base for Al Qaeda.  Failure in AF could lead to another 911.