In this monograph, Dr. Norman Cigar provides Special Operations Forces (SOF) commanders and planners with an overview of Al-Qaeda in the Arabian Peninsula’s (AQAP) operational framework and presence in the area. He analyzes the strategic and operational issues that confront policymakers in responding to the threat posed by AQAP within Yemen’s challenging social, political, and physical environment. This monograph presents the far-reaching implications for SOF, from recognizing the nuances of Yemen’s tribal-based human terrain to understanding key relationships, rivalries, and competition between AQAP and other Yemeni players. AQAP will likely continue to represent a threat to U.S. interests and regional stability for the foreseeable future.