Unconventional warfare (UW) is broadly defined as "military and quasi-military operations other than conventional warfare" and may use covert forces or actions such as subversion, sabotage, espionage, biowarfare, sanctions, propaganda or guerrilla warfare. This is typically done to avoid escalation into conventional warfare as well as international conventions.

Conventional warfare is a form of warfare conducted by using conventional weapons and battlefield tactics between two or more states in open confrontation. The forces on each side are well-defined and fight by using weapons that target primarily the opponent's military. It is normally fought by using conventional weapons, not chemical, biological, radiological, or nuclear weapons.