The correct matching of the United Nations Peacekeeping Operations with their respective periods of operation is as follows:
- UNMIL (United Nations Mission in Liberia): Established in September 2003 following the end of the Second Liberian Civil War, this mission aimed to support the implementation of the ceasefire agreement and the peace process. It officially closed on March 30, 2018. Thus, A matches 3.
- MINURCAT (United Nations Mission in the Central African Republic and Chad): Established in September 2007 to protect civilians, promote human rights, and support regional peace in the face of spillover violence from the Darfur conflict. Its mandate officially ended on December 31, 2010. Thus, B matches 1.
- MINUSTAH (United Nations Stabilization Mission in Haiti): Established in April 2004 after the 2004 Haitian coup d'état to restore a secure and stable environment. The mission officially ended on October 15, 2017, transitioning to a smaller justice support mission (MINUJUSTH). Thus, C matches 4.
- UNMISET (United Nations Mission of Support in East Timor): Established on May 20, 2002, to provide assistance to the newly independent nation of East Timor (Timor-Leste) in developing core administrative structures and maintaining security. It successfully completed its mandate on May 20, 2005. Thus, D matches 2.
Therefore, the correct matching is A-3, B-1, C-4, D-2.
