The United Nations Operation in the Congo (French: Opération des Nations Unies au Congo, abbreviated ONUC) was a United Nations peacekeeping force which was deployed in the Republic of the Congo in 1960 in response to the Congo Crisis. The ONUC was the UN's first peacekeeping mission with significant military capability, and remains one of the largest UN operations in size and scope.
The Congo descended into chaos and disorder after it became independent from Belgium on 30 June 1960. This prompted a swift return of Belgian troops, under the pretext of restoring order and protecting its nationals.