Game Changers in US Defense Strategy: An Examination of the Causes Behind the Increased Emphasis on Irregular Warfare Since 9/11

Despite the vast research devoted to the shifting focus of the defense strategy toward irregular operations and developing a counterinsurgency doctrine since September 11, 2001, little is known about the driving political forces behind the process. Most assume that the strategy has shifted because after ten years embroiled in two wars—Iraq and Afghanistan—the United States has learned that conventional operations do not work against unconventional enemies. While this is true, how and why the strategy is integrated at the policy level is less well understood. Therefore, the purpose of this study is to fill in this void. An examination of the Quadrennial Defense Reviews (QDR) from 2001, 2006, and 2010 provides solid evidence of the evolution of the defense strategy since 9/11. This study includes an overview of two major theories explaining decision-making in security studies—national interest and bureaucratic politics—which will then act as the lenses through which the doctrinal changes are investigated. Articles written on the respective QDRs coupled with an interview with Dr. Steven Metz, a leading expert in the field of national defense, round out the discussion of the driving forces behind the strategic shift to irregular warfare. This study concludes that both national interest and bureaucratic politics influenced the strategic shift since 9/11, albeit to varying degrees—national interest had the strongest effect in 2001, and then different components of the bureaucratic politics model intertwined with the national interest motivation as new “players” entered the “game” along the way. This investigation demonstrates that political prowess is just as important as the security environment when it comes to transforming the United States defense strategy.