The U.S. Army/Marine Corps Counterinsurgency Field Manual: U.S. Army Field Manual No. 3-24 : Marine Corps Warfighting Publication No. 3-33.5

Counterinsurgency is not just thinking man's warfare—it is the graduate level of war.
—Special Forces Officer in Iraq, 2005

This chapter provides background information on insurgency and counterinsurgency. The first half describes insurgency, while the second half examines the more complex challenge of countering it. The chapter concludes with a set of principles and imperatives that contribute to success in counterinsurgency.

1-1. Insurgency and counterinsurgency (COIN) are complex subsets of warfare. Globalization, technological advancement, urbanization, and extremists who conduct suicide attacks for their cause have certainly influenced contemporary conflict; however, warfare in the 21st century retains many of the characteristics it has exhibited since ancient times. Warfare remains a violent clash of interests between organized groups characterized by the use of force. Achieving victory still depends on a group's ability to mobilize support for its political interests (often religiously or ethnically based) and to generate enough violence to achieve political consequences. Means to achieve these goals are not limited to conventional forces employed by nation-states.

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