The fact of the matter is that the locus of terrorism has pivoted west away from AfPak (largely due to our military efforts) and towards the Arabian Peninsula and the Maghreb. Yemen has been in an effective state of turmoil since 2011 during which AQAP has been been able to capitalize and expand. The Yemen government has been warring against AQAP in the south for over a year now. AQAP is estimated to be in the thousands now rather than the hundreds it was in 2010.
Triage for a Fracturing Yemen - By April Longley Alley | The Middle East Channel
Losing Yemen - By Gregory Johnsen | Foreign Policy
Building a Yemeni state while lossing a nation - By Silvana Toska | The Middle East Channel