Self Defense

Self-defense (or self-defense; see spelling differences) is a countermeasure that involves defending oneself, one's property or the well-being of another from physical harm. The use of the right of self-defense as a legal justification for the use of force in times of danger is available in many jurisdictions, but the interpretation varies widely. To be acquitted of any kind of physical harm-related crime (such as assault and battery and homicide) using the self-defense justification, one must prove legal provocation, meaning that one must prove that they were in a position where not using self-defense would most likely lead to significant injury to life, limb, or property.
In politics, the concept of national or mutual self-defense to counter a war of aggression refers to a defensive war organized by the state and is one possible criterion in the just war theory.