July 10, 1978, the President Mokhtar ould Daddah is reversed by a military “coup d'etat” stirred up by several officers who put in power the lieutenant colonel Moustapha Ould Mohamed Saleck. A Military Committee of National Reformation assumes all powers. He manages to obtain a cease-fire with the POLISARIO. The new nasty leaders are destabilized because of their inexperience, of the internal quarrels and the hostility of France.

April 6, 1979, a “pronunciamiento” brings the Lieutenant-colonel Ahmed ould Bouceif to the head of the Government. A Military Committee for National Safety is set up. A new political reorientation is initiated. But Colonel Bouceif disappears little afterwards in an air crash off Dakar on May 31, 1979. Colonel Haidalla takes the head of the military junta on June 2. Colonel Ould Mohamed Saleck is removed from his functions and is replaced by Colonel Louly, as honorary President of the CMSN. Backed by left-wing political groups and from the pro-Polisario, he signs a cease-fire on August 5, 1979 with the Polisario in Algiers and then withdraws from Western Sahara. Morocco occupies from now on the totality of the Sahara. January 4, 1980, colonel Haidalla takes over all powers.

Between 1979 and 1984 several putsch attempts are thwarted. The most spectacular is held on March 16, 1981. Colonels Bah Ould Abdel Kader and Ahmed Salem Ould Sidi try to seize power. It was a failure. They are arrested the same day and killed after summary court proceedings. Gradually, the Haidalla regime become isolated and fills the prisons from opponents. The opposition mainly animated by the AMD (Alliance for Democratic Mauritania) is extended to several groups: Baathists, pro-Libyans…

December 12, 1984, colonel Maaouiya Ould Sid Ahmed Taya takes reins of power after a non-violent “coup d'etat”. The policy of the new head of state results in the emergence of a beginning of democracy. Local elections are organized in the thirteen regional capitals in 1986 then in 1988 in the rural moughataa and hundred sixty-four rural communes. It is a first in the history of the country. At the same time reforms liberalize the economy and relations are re-established with the institutions of Bretton Wood. The growth of the economy begins again gradually.

In 1989, terrible confrontations oppose Mauritanians and Senegalese and made many victims on both sides. The tension between the two countries had persisted for a certain while, fuelled by the agitation of activists Poulars Mauritanians following the failure of the attempted “coup d'etat” of October 1987. This “coup” prepared by Negro African soldiers is discovered of in time, leading to the arrests of individuals and poulars military. The authorities begin to dismantle the networks of supports for the putschists. This led to many arrests, even with exactions in an atmosphere of sharp ethnic tensions.

An active anti-Mauritanian campaign in the Senegal press added to the action of activists of Flam revived the tension and brought about the events of April 1989. Thousands of shops belonging to Mauritanians are plundered in Senegal, their owners pursued. Hunting for Maures in Senegal and also the Senegalese who suffered similar treatments in Mauritania caused many victims. The Mauritanians and the Senegalese’s were repatriated on each their respective side of the border. Following in these steps and ensuing from the tensions hundreds of Mauritanians Negro-Africans are deported on the other side of the border.

Diplomatic relations were broken between Senegal and Mauritania, in August. The very high tensions in 1989 and 1990 started to drop since 1991 to lead to the resuming of the relation’s en1992 and the reopening of the border on May 2 of the same year.