The events of September 11, 2001, catapulted America's military into two wars with others looming on the horizon. The type of warfare they are conducting is far different from what they had trained for the last quarter of a century. The enemy and environment in which they fight is different and the expectations placed on them have changed as well. In order to guide its actions the Army in concert with the Marine Corps has produced a new counterinsurgency doctrine with the creation of FM 3-24 Counterinsurgency. Although new to today's military, the type of conflict in which they are engaged is not novel. America and Great Britain as well as many other countries have fought counterinsurgencies in the past. This monograph analyzes the successful counterinsurgency efforts of the United States in Greece from 1947 to 1949 and Great Britain in Oman from 1964 to 1975 through the optical of the principles, paradoxes and imperatives advocated in FM 3-24.