Terrorism
Terrorist acts frequently have a political purpose. Some official, governmental definitions of terrorism use the criterion of the illegitimacy or unlawfulness of the act. to distinguish between actions authorized by a government (and thus "lawful") and those of other actors, including individuals and small groups. For example, carrying out a strategic bombing on an enemy city, which is designed to affect civilian support for a cause, would not be considered terrorism if it were authorized by a government. This criterion is inherently problematic and is not universally accepted, because: it denies the existence of state terrorism. An associated term is violent non-state actor.
Strategy and tactics of guerrilla warfare
In some cases, the use of terrorism can be an aspect of guerrilla warfare. Terrorism is used to focus international attention on the guerrilla cause, kill opposition leaders, extort money from targets, intimidate the general population, create economic losses, and keep followers and potential defectors in line. As well, the use of terrorism can provoke the greater power to launch a disproportionate response, thus alienating a civilian population which might be sympathetic to the terrorist's cause. Such tactics may backfire and cause the civil population to withdraw its support, or to back countervailing forces against the guerrillas.