Peacekeeping is an activity that aims to create the conditions for lasting peace. It is distinguished from both peacebuilding and peacemaking.

Peacekeepers monitor and observe peace processes in post-conflict areas and assist ex-combatants in implementing the peace agreements they may have signed. Such assistance comes in many forms, including confidence-building measures, power-sharing arrangements, electoral support, strengthening the rule of law, and economic and social development. Accordingly UN peacekeepers (often referred to as Blue Beret because of their light blue berets or helmets) can include soldiers, police officers, and civilian personnel.

The United Nations Charter gives the United Nations Security Council the power and responsibility to take collective action to maintain international peace and security. For this reason, the international community usually looks to the Security Council to authorize peacekeeping operations.

Most of these operations are established and implemented by the United Nations itself, with troops serving under UN operational control. In these cases, peacekeepers remain members of their respective armed forces, and do not constitute an independent "UN army", as the UN does not have such a force. In cases where direct UN involvement is not considered appropriate or feasible, the Council authorizes regional organizations such as the North Atlantic Treaty Organization (NATO), the Economic Community of West African States, or coalitions of willing countries to undertake peacekeeping or peace-enforcement tasks.

Hervé Ladsous is the United Nations Under-Secretary-General for Peacekeeping Operations. He was appointed to this position by the United Nations Secretary-General Ban Ki-moon on 2 September 2011.

Prior to this appointment, Ladsous served in France’s Foreign Service for four decades, during which he held a number of high-ranking positions. His posts included Chief of Staff to the Minister for Foreign Affairs, Ambassador to China, Indonesia and Timor-Leste, Spokesperson for the Foreign Ministry and Director General for Asia and Oceania, as well as Permanent Representative to the Organization for Security and Co-operation in Europe (OSCE) in Vienna.

He joined the Foreign Ministry of France in 1971 and was stationed in Hong Kong, Canberra, Beijing, and Geneva. He also acted as Deputy-Director General of the Department for the Americas and served in Haiti as ad interim Chargé d'affaires. Afterwards, he was appointed as Deputy Permanent Representative to the United Nations in New York.

Ladsous has a degree in law and a diploma in Chinese and Indonesian Malay from the National School of Oriental Studies in France. He is married and has three children.