Reality and changes

To begin with the strategic case for staying, it is not enough to use buzzwords like “terrorism,” and somehow link the Afghan War to every significant terrorist threat to the United States. It is all too clear that Afghanistan now has marginal strategic interest to the United States. It no longer is a meaningful center of international terrorism. Al Qaeda’s main fighting elements are now in the Middle East and Africa and Al Qaeda central is based in Pakistan. 

CSIS: The Reality Beyond Zero and 10,000: Choosing a Meaningful Option in Afghanistan, February 4, 2014 

The vast weight of al Qaeda manpower and funding (the sum of both AQC and its official affiliates) currently goes to support insurgencies and warfighting, including both foreign fighters and regional residents under the same flag. While this activity is obviously concentrated in Syria, every major al Qaeda affiliate has followed the same course to some extent, deploying forces to hold territory and attempt governance from Mali to Somalia to Yemen.

Al Qaeda is clearly still in the terrorism business, but terrorism is no longer its flagship product -- in the same way that the Mac no longer dominates the Apple brand. Terrorism is the product on which the organization was built -- and it still matters -- but it is no longer the main line of business. 

Foreign Policy: War on Error, February 5, 2014