The United Nations was established in 1945 "to save succeeding generations from the scourge of war" and one of its main purposes is to maintain international peace and security. The UN has often been called upon to prevent disputes from escalating into war, or to help restore peace when armed conflict does break out, and to promote lasting peace in societies emerging from wars.
The different instruments of the UN's peace efforts come into play at different stages of conflict. The boundaries however between conflict prevention, peacemaking, peacekeeping, peacebuilding and peace enforcement have become increasingly blurred. Peace operations are rarely limited to one type of activity.