Spanish withdrawal While Spain started negotiating a handover of power in mid 1975, it ceded the administrative control of the territory to Mauritania and Morocco only after signing the
Madrid Accords. However, on 31 October 1975, Moroccan troops crossed into the territory from the north-east, advancing towards
Mahbes and
Farciya. The Moroccan government organized the
Green March of some 350,000 Moroccan citizens, escorted by around 20,000 troops, who entered Western Sahara, trying to establish Moroccan presence. The
United Nations did not officially recognize the accord, considering Spain as the administrative power of the territory. In late 1975, as a result of the Moroccan advance, tens of thousands of Sahrawis fled Morocco-controlled cities into the desert, building up improvised refugee camps in
Amgala,
Tifariti and
Umm Dreiga.
Moroccan invasion On 11 December 1975, the first Moroccan troops arrived in El Aaiún, and fighting erupted with the Polisario Front. On 26 February 1976, Spain officially announced its full withdrawal from the area. which was unable to fend off the attacks. After repeated strikes at the country's principal source of income, the
iron mines of Zouerate, the Government was nearly incapacitated by the lack of funds and the ensuing internal disorder.
Ethnic unrest in the
Mauritanian Armed Forces also strongly contributed to the ineffectiveness of the army: forcibly
conscripted black Africans from the south of the country resisted getting involved in what they viewed as a northern intra-Arab dispute, and the tribes of northern Mauritania often sympathized with Polisario, fearing possible Moroccan regional ambitions and presenting perceived increasing dependence of the Daddah regime on Moroccan support. In 1977, France intervened after a group of French technicians was taken prisoner during a raid on the Zouerate iron mines, codenaming its involvement
Opération Lamantin. The
French Air Force deployed
SEPECAT Jaguar jets to Mauritania in 1978 under the orders of President
Valéry Giscard d'Estaing, which repeatedly bombed Polisario columns headed for Mauritania with napalm. The Polisario Front launched a raid on the capital
Nouakchott, during which Polisario chief and leader El Ouali was killed, and was replaced by
Mohamed Abdelaziz, with no letup in the pace of attacks. Under continued pressure, the Daddah regime finally fell in summer 1978 to a
coup d'état led by war-weary military officers, who immediately agreed to a
ceasefire with the Polisario. A comprehensive peace treaty was signed on 5 August 1979, in which the new Mauritanian government recognized Sahrawi rights to Western Sahara and relinquished its own claims. Mauritania withdrew all its forces and would later proceed to formally recognize the Sahrawi Arab Democratic Republic, causing a massive rupture in relations with Morocco. King
Hassan II of Morocco immediately claimed the area of Western Sahara evacuated by Mauritania (
Tiris al-Gharbiya, roughly corresponding to the southern half of Río de Oro), which was unilaterally
annexed by Morocco on 11 August 1979.
Stalemate (1980s) by the Polisario Front during the war From the mid-1980s Morocco largely had kept Polisario troops off by building a huge
berm or sand wall (the
Moroccan Wall). The Moroccan army stationed a number of troops roughly the same size as the entire Sahrawi population to defend the wall, enclosing the
Southern Provinces, the economically useful parts of Western Sahara (
Bou Craa,
El-Aaiun, Smara etc.). This stalemated the war, with no side able to achieve decisive gains, but artillery strikes and sniping attacks by the guerrillas continued, and Morocco was economically and politically strained by the war. Morocco faced heavy burdens due to the economic costs of its massive troop deployments along the Wall. Economic and military aid was sent to Morocco by
Saudi Arabia, France and the United States to relieve the situation but matters gradually became unsustainable for all parties involved.
Escalation (1989–1991) On 7 October 1989, Polisario launched a massive attack against Moroccan troops in Guelta Zemmour (Centre of Western Sahara) and Algeria but sustained heavy casualties and withdrawn after leaving more than 18
tanks burning and a dozen more vehicles. This setback led the Polisario to consider a ceasefire. The
1991 Tifariti offensive was the last military operation and successful maneuver in the Western Sahara War launched by Moroccan forces against the Sahrawi
guerrilla fighters of the
Polisario Front. During August–September 1991 the Royal Moroccan Army (RMA) conducted offensive operations in the areas of Mehaires, Tifariti, and Bir Lahlou and cleared the area of any Polisario presence. == Cease-fire and aftermath ==