Often treated by Americans as an exceptional form of warfare, insurgency is anything but. Spanning the globe, centuries, and societies, insurgency is quite common. Given the threat insurgency presents to U.S. interests and allies around the world, the importance of counterinsurgency is no surprise. However, history has shown that insurgencies are rarely defeated by outside powers. Rather, the best role for outsiders is an indirect one: training, advising, and equipping the local nation, which must win the war politically and militarily. And while counterinsurgency might seem to be a task most suited to ground forces, air power has much to contribute. These facts combine to suggest that advising, training, and equipping partner air forces will be a key component of U.S. counterinsurgency efforts worldwide. The authors note that, if the Air Force is to participate in these tasks, it will need to make counterinsurgency an institutional priority, developing the capabilities of its personnel both as advisors and trainers and as combatants, as well as developing the necessary institutional support structures.