Devoid of a clear textual foundation in the UN Charter, the phenomenon of peacekeeping operations originated as a practical response to the failure of the system of collective security as originally envisaged by the founders. Since the first UN peacekeeping mission – the UN Truce Supervision Organization (UNTSO) established in 1948 to supervise the cessation of hostilities between Israel and neighbouring Arab states – a total of sixty-three peacekeeping operations have been deployed around the world. In 2005–10 alone, new peacekeeping missions were established in Sudan (UNMIS), East Timor (UNMIT), Darfur (UNAMID), Chad (MINURCAT) and the Democratic Republic of Congo (MONUSCO). By 2010 the UN managed seventeen operations comprising more than 117,000 military, police and civilian personnel across five continents.
Peacekeeping has evolved over time to meet changing political situations and demands. At their inception during the cold war, peacekeeping operations performed a predominantly stabilising role through the military supervision of inter-state ceasefires and limited peace agreements, mostly in the Middle East. Under what is commonly known as the ‘traditional interposition model’, the majority of the fifteen operations established before 1989 were based on an unarmed or lightly armed military observer presence. With the exception of the intervention in Korea in 1950, which was in any event an example of peace enforcement rather than peacekeeping, these operations were undertaken with the consent of the host state(s). Obliged not to use force except in self-defence and with very little control over territory, such missions gave rise to little potential for abuse of the rights of individuals.