Article 51 Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security.

Article 107 Nothing in the present Charter shall invalidate or preclude action, in relation to any state which during the Second World War has been an enemy of any signatory to the present Charter, taken or authorized as a result of that war by the Governments having responsibility for such action.

Article 2 (4) - Prohibition of threat or use of force in international relations. Article 2 (4) of the Charter prohibits the threat or use of force and calls on all Members to respect the sovereignty, territorial integrity and political independence of other States.

UN Charter Article 2(4) forbids states from using force in their international relations. Exceptions to this prohibition are acts taken in self-defence under UN Charter Article 51 or under the auspices of a UN Security Council authorization to use force under Article 42.