War is a state of conflict, generally armed, between two or more entities. It is characterized by intentional violence on the part of large bodies of individuals organized and trained for that purpose. On the national level, some wars are fought internally between rival political factions (civil war); others are fought against an external enemy.
Wars have been fought
- in the name of religion
- in self-defense
- to acquire territory or resources
- and to further the political aims of the aggressor state’s leadership
The Crusades to the Holy Land are the best known of the religious wars associated with the term, beginning in 1095 and lasting some two centuries.
Situations without a nexus to the hostilities can arise where soldiers may act in self-defense. For example, a soldier may use force in defense of self or others during occupation in response to a criminal attack that is unrelated to the armed conflict.
A territorial war in a civilized country is an organized war directed according to plan. In its general outline the command is expressly centralized, although in detail it leaves much more independence and initiative to the subordinate commanders than is the case in frontal warfare.
In broadest definition, political warfare is the employment of all the means at a nation's command, short of war, to achieve its national objectives. Such operations are both overt and covert.
How Countries Fight Their Wars