51: Nothing in the present Charter shall impair the inherent right
of individual or collective self-defense 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. Measures taken by Members in the
exercise of this right of self-defense shall be immediately reported to the Security
Council and shall not in any way affect the authority and responsibility of the
Security Council under the present Charter to take at any time such action as
it deems necessary in order to maintain or restore international peace and security.