Perpetual war is a war that has no clear ending conditions, and seems likely to flare up from time to time for the forseeable future. The War on Terrorism is widely considered to be such a perpetual war, as terrorism is rarely under the control of a single authority who can clearly surrender - and usually can keep recruiting even under extreme pressure. The Bush doctrine of preemptive strikes against nations with certain technological and military capacities that 'may threaten' the United States also implies a perpetual war, as these capacities proliferate into the hands of less and less friendly nations, and become cheaper to exploit in a threatening way.

See also: rogue state