Insurgency and counterinsurgency as types of warfare are currently subject to considerable attention due to the nature of the high-profile struggles underway in Afghanistan and Iraq. It is prudent to note that neither insurgency nor the strategy and tactics required to combat it represent new phenomena. A large body of experience and literature from the twentieth century and earlier exists that addresses both sides of the insurgent struggle. Some characteristics of insurgencies are largely immutable, since insurgency is ultimately a form of warfare that is adopted when a combatant has limited resources and limited choices for how to fight against a more powerful adversary. Today as in the past, these characteristics include employment of small-unit attacks, ambushes, assassinations, propaganda activity, and the development of covert infrastructure. Nevertheless, the primary insurgencies active in the twenty-first century are marked by important differences from earlier struggles, particularly in the areas of motivation and inspiration. Rather than being quintessentially political and interested in local or national grievances, many contemporary insurgencies are at their core linked to a particular interpretation of Islam. Thus, these insurgencies represent a war of religion, not of politics, economics, or ethnicity. Islamist insurgencies are likely to be uncompromising and averse to negotiation, absolutist and pan-national in their goals, and willing to justify the mass slaughter of non-combatants who do not share their religious vision.
Counterinsurgent strategies that take into account the religious world-view of their opponents are better equipped for success than counterinsurgent efforts that ignore or minimize the radical Islamist dimensions of the struggle. Saudi Arabia offers an example of a counterinsurgency campaign that has been tailored to deal with an Islamist challenge. Modern communications and technology may link disparate Islamist insurgencies to some degree, and might eventually provide a means of coordination and information sharing. In fact, this may already be occurring. Contests with Islamist insurgencies around the globe are likely to continue for a protracted period.