The mission intended to investigate the political situation in the Spanish Sahara, as well as the conflicting claims to the territory:
Spain had administered the Spanish Sahara since the Berlin Congress in 1884, but had announced it was pulling out of the territory. A Madrid-backed political party, the Partido de Unión Nacional Saharaui, argued for a gradual transition to independence and demanded privileged relations between Spain and a future Western Sahara.
Morocco invoked historical ties between its royal family and the :Category:Sahrawi tribes|Sahrawi tribes, claiming the territory as its Southern Provinces.
The United Nations had since 1966 demanded that a referendum among the native population should determine the future status of the territory.
The mission
The mission was composed of three members. Its head was Simeon Aké, UN ambassador of the Côte d'Ivoire ; accompanying him were Marta Jiménez Martinez, a Cuban diplomat, and Manouchehr Pishva, from Iran. It toured Spanish Sahara on May 12–19, 1975, after initially having been denied entry by Spanish authorities. On May 8–12 and again on May 20–22, it visited Madrid, Spain; and from May 28 to June 1, it toured the neighbouring countries Mauritania, Morocco and Algeria; in Algeria - which supported the Polisario since late 1974 - it also met with leaders of the Polisario Front.
Findings of the mission
Moroccan Sahara
In the territory, the mission encountered opposing demonstrations by the Polisario Front and the PUNS, both demanding independence, but differing in their approach to the Spanish authorities. Tony Hodges writes: The mission estimated the largest demonstration they witnessed, "organized by the Frente Polisario", in El-Aaiun on May 13, 1975, to have consisted of 15,000 people - significant, since a 1974 census by the Spanish authorities had set the total population at just below 75,000 people.
In Fes, King Hassan II repeated the Moroccan claim to the territory, and the mission witnessed "large pro-annexation demonstrations in towns in the far south of the country, near the Western Saharan border" that "left in no doubt the depth of popular support in Morocco for Hassan's campaign of 'reunification,' as well as his governments determination to achieve its objectives. The mission was informed that Morocco would not accept the inclusion of independence among the options to be put to the Western Saharans in a referendum. The only acceptable question was: 'Do you want to remain under the authority of Spain or to rejoin Morocco?'"
In Algeria, President Houari Boumedienne stated that "Algeria had no interest in Western Sahara other than to see the Sahrawi's right to self-determination respected". The mission also visited the Sahrawi communities in Tindouf, Oum el-Assel and Hassi Abdallah in Algeria, where they "were met by thousands of pro-POLISARIO demonstrators" and were shown Spanish officers of the Tropas Nómadas, held as prisoners-of-war by POLISARIO forces. POLISARIO General-Secretary El-Ouali Mustapha Sayed stated that "a referendum was unnecessary since it was now evident that the majority of Saharawis wanted independence, but said that that they would accept one, if the UN insisted, on condition that the Spanish administration had first been withdrawn and replaced by a 'national' administration, that all Spanish troops had been withdrawn and replaced by POLISARIO soldiers under UN and Arab League guarantees, and that all refugees had been allowed to return to the territory".
Consequences of the mission report
The mission presented its report to the United Nations on October 15, 1975. The results of the investigation were cited especially by the Polisario Front and its Algerian backers as supportive of their argument, but the debate was largely submerged by the presentation of the opinion of the International Court of Justice on October 16. The court argued that while there were historical ties between both Mauritania and Morocco to the tribes and lands of Spanish Sahara, neither country's claim sufficed to grant it ownership of the territory. The court also ruled that the Sahrawis possessed a right of self-determination, meaning that any solution to the problem of the status of Spanish Sahara had to be approved by the Sahrawi public. As a response to the ICJ verdict, King Hassan II of Morocco announced within hours of the release of the court's findings, that he would organize a Green March into Spanish Sahara to assume ownership of the territory.
