In US military doctrine, unconventional warfare (abbreviated UW) is one of the core activities of irregular warfare. Unconventional warfare is essentially support provided by the military to a foreign insurgency or resistance. The legal definition of UW is:
Unconventional Warfare consists of activities conducted to enable a resistance movement or insurgency to coerce, disrupt or overthrow an occupying power or government by operating through or with an underground, auxiliary or guerrilla force in a denied area.[1]