The primary question this thesis aims to answer is--did the Studies and Observation Group (SOG) covert and clandestine operations contribute significantly to the Vietnam War effort? The scope of research is an examination of SOG operations throughout the war. To determine SOG's contributions, research will answer the following secondary and tertiary questions: (1) What were the US strategic, operational, and tactical goals for Vietnam and how did they develop? (2) Did SOG contribute to the accomplishment of strategic, operational, and tactical goals in the Vietnam War? and (3) How did SOG missions affect enemy forces and their operations?By answering the primary, secondary, and tertiary questions, a conclusion may be drawn concerning the contributions of SOG in Vietnam as the primary headquarters for carrying out the unconventional war effort against the North Vietnamese. Lessons learned may apply to the use of similar unconventional warfare assets in the Global War on Terrorism.