Correspondence issued by the Government Accountability Office with an abstract that begins "Senior military officials recently testified before Congress that current and future adversaries are likely to use "hybrid warfare" tactics, a blending of conventional and irregular approaches across the full spectrum of conflict. In addition, several academic and professional trade publications have commented that future conflict will likely be characterized by a fusion of different forms of warfare rather than a singular approach. The overarching implication of hybrid warfare is that U.S. forces must become more adaptable and flexible in order to defeat adversaries that employ an array of lethal technologies to protracted, population-centric conflicts such as those in Iraq and Afghanistan. Department of Defense (DOD) officials have discussed the need to counter the continuum of threats that U.S. forces could face from nonstate- and state-sponsored adversaries, including computer network and satellite attacks; portable surface-to-air missiles; improvised explosive devices; information and media manipulation; and chemical, biological, radiological, nuclear, and highyield explosive devices. In light of references to "hybrid warfare" by senior military officials and possible implications it could have for DOD's strategic planning, Congress requested we examine: (1) whether DOD has defined hybrid warfare and how hybrid warfare differs from other types of warfare and (2) the extent to which DOD is considering the implications of hybrid warfare in its overarching strategic planning documents. On June 16, 2010, we met with congressional staff to discuss the preliminary results of our work. This report formally transmits our final response to Congress' request.
