Cease-fire in the context of "United Nations Mission for the Referendum in Western Sahara"

The Free Zone or Liberated Territories (Arabic: المنطقة الحرة, romanized: al-minṭaqa al-ḥurra) is a term used by the Polisario Front government of the Sahrawi Arab Democratic Republic, a partially recognized sovereign state in the western Maghreb, to describe the part of Western Sahara that lies to the east of a 2,200-kilometre (1,400 mi) border wall flanked by a minefield, often referred as the Berm, and to the west and north of the borders with Algeria and Mauritania, respectively. It is controlled by the Sahrawi Arab Democratic Republic, as opposed to the area to the west of the Berm, which is occupied by Morocco as part of its Southern Provinces. Both states claim the entirety of Western Sahara as their territory.

The zone was consolidated as a Polisario-held zone in a 1991 cease-fire between the Polisario Front and Morocco, which had been agreed upon together as part of the Settlement Plan. Morocco occupies the areas west of the Berm, including most of the territory's population. The cease-fire is overseen by the United Nations' MINURSO forces, charged with peacekeeping in the area and the organization of a referendum on independence.

Dag Hjalmar Agne Carl Hammarskjöld (English: /ˈhæmərʃʊld/ HAM-ər-shuuld, Swedish: [ˈdɑːɡ ˈhâmːarˌɧœld] ; 29 July 1905 – 18 September 1961) was a Swedish economist and diplomat who served as the second secretary-general of the United Nations from April 1953 until his death in a plane crash in September 1961. As of 2025, he remains the youngest person to have held the post, having been only 47 years old when he was elected. He was a son of Hjalmar Hammarskjöld, who served as Prime Minister of Sweden from 1914 to 1917.

Hammarskjöld's tenure was characterized by efforts to strengthen the newly-formed UN both internally and externally. He led initiatives to improve morale and organizational efficiency while seeking to make the UN more responsive to global issues. He presided over the creation of the first UN peacekeeping forces in Egypt (the UNEF) and the Congo (the ONUC) and personally intervened to defuse or resolve diplomatic crises. Hammarskjöld's second term was cut short when he died in a plane crash while en route to cease-fire negotiations during the Congo Crisis.

The Settlement Plan (Arabic: خطة التسوية, romanized: Khiṭṭah al-Taswiyah; Spanish: Plan de Arreglo) was an agreement between the ethnically Sahrawi Polisario Front and Morocco on the organization of a referendum, which would constitute an expression of self-determination for the people of Western Sahara, leading either to full independence, or integration with the Kingdom of Morocco. It resulted in a cease-fire which remained effective until 2020, and the establishment of the MINURSO peace force to oversee it and to organize the referendum. The referendum never occurred.