United Nations peacekeeping in the context of "United Nations Mission for the Referendum in Western Sahara"

The Department of Peace Operations (DPO) (French: Département des opérations de maintien de la paix) is a department of the United Nations (UN) charged with the planning, preparation, management, and direction of UN peacekeeping operations. Previously known as the Department of Peacekeeping Operations (DPKO), it was created in 1992 as part of a restructuring of the UN's peace and security apparatus. The DPO retains the core functions and responsibilities of its predecessor, with a greater emphasis on cohesion, integrating different resources and knowledge, and promoting human rights.

With an annual budget of roughly $6.5 billion as of 2020, the DPO is the largest UN agency by expenditure, exceeding the UN's own regular budget. As of March 2020, it oversaw 81,370 personnel serving in 13 peacekeeping missions.

Peacekeeping comprises activities intended to create conditions that favor lasting peace. Research generally finds that peacekeeping reduces civilian and battlefield deaths, as well as reduces the risk of renewed warfare.

Within the United Nations (UN) group of nation state governments and organizations, there is a general understanding that at the international level, peacekeepers monitor and observe peace processes in post-conflict areas, and may assist ex-combatants in implementing peace agreement commitments that they have undertaken. Such assistance may come in many forms, including confidence-building measures, power-sharing arrangements, electoral support, strengthening the rule of law, and economic and social development. Accordingly, the UN peacekeepers (often referred to as Blue Berets or Blue Helmets because of their light blue berets or helmets) can include soldiers, police officers, and civilian personnel.

The United Nations Transitional Authority in Cambodia (UNTAC) was a United Nations administrative and peacekeeping operation in Cambodia in 1992–93 formed following the 1991 Paris Peace Accords. This was the first occasion in which the UN directly assumed responsibility for the administration of an outright independent state (though the UN did administer the former Dutch territory of Netherlands New Guinea between 1962 and 1963 prior), rather than simply monitoring or supervising the area. The UN transitional authority organized and ran elections, had its own radio station and jail, and was responsible for promoting and safeguarding human rights at the national level.

The United Nations Protection Force (UNPROFOR; also known by its French acronym FORPRONU: Force de Protection des Nations Unies) was the first United Nations peacekeeping force in Croatia and in Bosnia and Herzegovina during the Yugoslav Wars. The force was formed in February 1992 and its mandate ended in March 1995, with the peacekeeping mission restructuring into three other forces (the United Nations Preventive Deployment Force (UNPREDEP) in the Republic of Macedonia, and the United Nations Confidence Restoration Operation in Croatia (UNCRO) in Croatia, with restructured UNPROFOR operations ongoing in Bosnia and Herzegovina until their replacement by NATO and EU missions in December 1995).

The Organisation of African Unity (OAU; French: Organisation de l'unité africaine, OUA) was an African intergovernmental organisation established on 25 May 1963 in Addis Ababa, Ethiopia, with 33 signatory governments. Some of the key aims of the OAU were to encourage political and economic integration among member states, and to eradicate colonialism and neo-colonialism from the African continent.

The absence of an armed force like the United Nations peacekeepers left the organization with no means to enforce its decisions. It was also unwilling to become involved in the internal affairs of member nations, prompting some critics to claim the OAU as ineffective in taking decisive action. Recognising this, in September 1999 the OAU issued the Sirte Declaration, calling for a new body to take its place. On 9 July 2002, the OAU's Chairman, South African President Thabo Mbeki, formally dissolved the OAU and replaced it with the African Union (AU), its immediate successor, which upholds many of the founding principles of the OAU.

The United Nations Transitional Administration in East Timor (UNTAET, Portuguese: Administração Transitória das Nações Unidas em Timor Leste), was a United Nations mission in East Timor that aimed to solve the decades-long East Timorese crisis in the area occupied by Indonesian military. UNTAET provided an interim civil administration and a peacekeeping mission in the territory of East Timor, from its establishment on 25 October 1999, until its independence on 20 May 2002, following the outcome of the East Timor Special Autonomy Referendum. The transitional administration was established by United Nations Security Council Resolution 1272 in 1999.

A rarity for United Nations peacekeeping missions, UNTAET involved the United Nations directly administering the territory of East Timor. The mission's responsibilities included providing a peacekeeping force to maintain security and order; facilitating and co-ordinating relief assistance to the East Timorese; facilitating emergency rehabilitation of physical infrastructure; administering East Timor and creating structures for sustainable governance and the rule of law; and assisting in the drafting of a new constitution and conducting elections.