War
War, organized armed conflict between groups of people or states. War is not found elsewhere in the animal kingdom. Since recorded history began, people have been involved in hostility for different aims: power, territory, wealth, ideological domination, security, or independence. Until modern times most wars were fought with limited means for limited aims, but modern weapons threaten mass destruction with their ability to eliminate whole populations, thus endangering the survival of the human race.
Additional topics
21st Century Webster's Family Encyclopedia21st Century Webster's Family Encyclopedia - Victoria to Waterloo, Battle of