Is President Obama's Afghanistan strategy working?

With Afghan President Hamid Karzai visiting Washington this week, The Post asked experts whether the surge in Afghanistan was working. Below are contributions from Erin M. Simpson, Gilles Dorronsoro, Kurt Volker, John Nagl, Thomas H. Johnson and Andrew J. Bacevich. - Is President Obama's Afghanistan strategy working?

In Afghanistan, plenty of reasons to worry
The hard work ahead in Afghanistan - Hamid Karzai