Irregular warfare

Irregular warfare is warfare in which one or more combatants are irregular military rather than regular forces. Guerrilla warfare is a form of irregular warfare, and so is asymmetric warfare.

The overuse of the term 'warfare' in contemporary military terminology to describe both a specific type of engagement and the type of forces participating in it can lead to false conclusions. A guerrilla unit that is made of commandos is a regular unit conducting asymmetric warfare whereas an irregular band of fighters can engage combat in a tactical infantry firefight if well led and well equipped, fighting like a conventional unit.

Irregular warfare favors indirect and asymmetric warfare approaches, though it may employ the full range of military and other capabilities, in order to erode the adversary’s power, influence, and will. It is inherently a protracted struggle that will test the resolve of a state and its strategic partners. Concepts associated with irregular warfare are older than the term itself.

The word "regular" is used in the term "regular armed forces" which comes from the Third Geneva Convention of 1949. The International Committee of the Red Cross (ICRC) is a non-governmental organization primarily responsible for, and most closely associated with, the drafting and successful completion of the Third Geneva Convention Relative to the Treatment of Prisoners of War (“GPW”). The ICRC provided commentary saying that "regular armed forces" satisfy four Hague Conventions (1899 and 1907) (Hague IV) conditions. In other words, "regular forces" must satisfy the following criteria:

On the other hand, "irregular forces" is a term in international humanitarian law referring to a category of combatants consisting of individuals forming part of the armed forces of a party to an armed conflict, international or non-international, but not belonging to that party's regular forces and operating in or outside of their own territory even if the territory is under occupation. As such, it is implicit that irregular warfare is warfare where a major party in the conflict is a part of irregular forces.

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