Theannexation of Western Sahara occurred in two stages: 1976 and 1979. Shortly afterSpain gave up control overSpanish Sahara in 1975, bothMauritania andMorocco occupied the territory. On 14 April 1976, the two countries annexed it between themselves via theWestern Sahara partition agreement. However, on 5 August 1979, Mauritania renounced all territorial claims toWestern Sahara and withdrew its troops, prompting Morocco to extend its annexation to formerly Mauritanian-controlled areas.[1][2][3]
SinceWorld War II, it has been held ininternational law that any act ofannexation is illegal. Likewise, theUnited Nations regards the Moroccan annexation of Western Sahara asnull and void, such that the territory is not a legal part of Morocco and it remains subject to the international guidelines for amilitary occupation.[4]
As Morocco and theUnited States have had a close relationship since the former's independence,Morocco has enjoyed full American support throughout theWestern Sahara conflict.[5] In exchange for theIsrael–Morocco normalization agreement in 2020, the United States officially recognized Western Sahara as part of Morocco, and urged theSahrawi Arab Democratic Republic to "negotiate a mutually acceptable solution" using Morocco'sWestern Sahara Autonomy Proposal as the only framework. In 2023,Israel formally recognized Moroccan sovereignty over Western Sahara.[6]
As Spain began the process of decolonization ofWestern Sahara, a number of international bodies were asked to opine on the territories' status. TheUN visiting mission to Spanish Sahara, carried out in May 1975, published their report on 15 October 1975. On the next day, on 16 October 1975, theInternational Court of Justice Advisory Opinion on Western Sahara was published. Both reports supported a referendum of the people of Western Sahara; the ICJ report acknowledged that Western Sahara had historical links with Morocco and Mauritania, but not sufficient to prove the sovereignty of either State over the territory at the time of the Spanish colonization. The population of the territory thus possessed the right ofself-determination.
On 31 October 1975, Moroccan troops began an invasion of Western Sahara from the north.[7]
The Moroccan government’sGreen March took place on 6 November 1975, in which 350,000 unarmed Moroccans converged on the city ofTarfaya in southern Morocco and waited for a signal from KingHassan II of Morocco to cross the border in a peaceful march.
TheMadrid Accords were signed by Spain with Morocco and Mauritania on 14 November 1975.[8]
The Moroccan and Mauritanian annexations were resisted by thePolisario Front, primarily by guerrilla warfare, which had gained backing fromAlgeria.[9]
Following the occupation, on 14 April 1976, theWestern Sahara partition agreement was signed to formalize the annexation and agree the borders between Morocco and Mauritania. Morocco annexed the northern two-thirds of Western Sahara as itsSouthern Provinces, and Mauritania annexed the southern third asTiris al-Gharbiyya.[2][3]
On 5 August 1979, Mauritania withdrew due to pressure from Polisario, including a bombardment of its capital and other economic targets.
On 11 August 1979, Morocco extended its control and annexed the rest of the territory.[2][3]
Armed Conflicts over "non-self-governing territories" in the Name of "Restoration of Inherent Territories".[10][11][12]
To sum up the legal status: Western Sahara is not a part of Morocco and Morocco has no legal title or claim to the territory. Since the annexation is illegal, it is null and void, and Morocco is therefore, legally speaking, an occupying power. Morocco has an obligation to respect the right of the people of Western Sahara according to the law of occupation and to end its illegal annexation and occupation of Western Sahara.