Perpetual war
Perpetual war is a war that has no clear ending conditions, and seems likely to flare up from time to time for the foreseeable future.
In past history
Examples of seemingly interminable wars were the Hundred years war (1337-1453), the Thirty years war (1618-1648), and the liberation of Vietnam by North Vietnamese and Viet Cong, who fought against Japanese, French, U.S. and southern Vietnamese forces - 1942 -1973).
In recent history
The Cold War, lasting almost 50 years, is an example of such a war, although largely fought by the major powers through a large number of small "proxy wars", where the major powers provided aid to various local factions engaged in so-called "wars of national liberation". When the major powers became directly involved, as the U.S. in the war in Vietnam, or the Soviet Union in Afganistan the consequenses were generally a disaster for the major power.
In current events
The current War on Terrorism is widely considered to be an attempt to create a state of 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 greater numbers of less friendly nations, and become cheaper to exploit in a threatening way.
In socieconomics and politics
Some analysts posit that a state of perpetual war is an aid to (and is promoted by) the powerful members of dominant political and economic classes in maintaining their positions of economic superiority (or more radically, of economic exploitation) over the common people. (As this analysis was first expounded by Karl Marx, it is often attacked solely on that basis, but the initial authorship does not reduce its potential or arguable validity.) Supporters of this viewpoint (particularly Noam Chomsky, Ralph Nader, and Michael Moore) clearly state their observations that war is of great benefit to certain industries and hence to the investors and executives of these industries. They also point out that these same people excercise inordinate political power, either indirectly, through politicians they control through campaign contributions, or directly, by becoming the politicians, while also creating obstacles to reform such as supporting the gerrymandering of "safe" electoral districts and by attempting to prevent electoral innovations such as instant runoff or proportional representation.
In the media
Economic class dominance of politics becomes progressively easier in a modern democratic republic such as the United States due to the continuing development of interlocking relationships between those who benefit directly from war and the large and powerful media companies that indirectly benefit and who can shape the presentation of the effects and consequences of war. These media conglomerates can also effectively demean the character and motives of opponents of war and thus (as is the goal) the viewpoints, perceptions, and (ultimately) the choices of the electorate. Some radical and progressive observers argue that a particularly insidious method of these powers is to influence both sides of the argument through electoral primaries, thus creating the "Republicrat.
In literature
The novel 1984 by George Orwell was written (in 1948) from the (fictional) viewpoint of a citizen of one of three world dominating superstates. These nations are in a state of perpetual war with each other. The state of war is used by each of the states to justify the control of their populations using Stalinist or other methods.
See also