Just Cause  Wars are just if the cause is just. Nations should be allowed to defend themselves from aggression, just as individuals are permitted to defend themselves against violence. In the UN Charter, signed in the wake of World War II, article 2, paragraph 4 altogether prohibits the use or threat of force with only self-defence, as stated in article 51, permitted as a justification to the resort to arms. [1]  [1] United Nations. (1945, June 26). Chapter I: Purposes and Principles. Retrieved May 9, 2011, from Charter of the United Nations: