"America began the 20th century with military forces engaged in counterinsurgency (COIN) operations in the Philippines. Today, it is conducting similar operations in Afghanistan, Iraq, and a number of other countries around the globe. During the past century, Soldiers and Marines gained considerable experience fighting insurgents in Southeast Asia, Latin America, Africa, and now in Southwest Asia and the Middle East. Conducting a successful counterinsurgency requires an adaptive force led by agile leaders. While every insurgency is different because of distinct environments, root causes, and cultures, all successful COIN campaigns are based on common principles. All insurgencies use variations of standard frameworks and doctrine and generally adhere to elements of a definable revolutionary campaign plan. In the Information Age, insurgencies have become especially dynamic. Their leaders study and learn, exchange information, employ seemingly leaderless networks, and establish relationships of convenience with criminal gangs. Insurgencies present a more complex problem than conventional operations, and the new variants have a velocity that previous historical insurgencies never possessed."
Small Wars Center of Excellence: http://www.smallwars.quantico.usmc.mil/
Military Review (March-April 2006), p.49-53