Libya invaded Chad in 1980, to help Oueddei remain in power and to forward an expansionist policy that projected to unify politically Libya and Chad. Before, The Libyans had already occupied a narrow strip of land known as the Aouzou Strip in 1972-73. France and the United States responded by aiding Habré in an attempt to contain Libya's regional ambitions under Muammar al-Qaddafi. Civil war deepened. In December, 1980 Libya occupied all of northern Chad, but Habré defeated Libyan troops and drove them out in November, 1981. By this stage France and neighbouring Libya were intervening repeatedly to support one side against another. Habré in 1982 conquered the capital ousting President Oueddei, and assumed overall control of the state. His eight year reign led to immense political turmoil, with human rights organisations accusing him of having ordered the execution of thousands of political opponents and members of tribes thought hostile to his regime. In 1983, Qaddafi's troops occupied all of the country north of Koro Toro. The United States used a clandestine base in Chad to train captured Libyan soldiers, whom it tried to organize into an anti-Qaddafi force. Habré's aid from the USA and France helped him to win the war against Libya. The Libyan occupation of the north of Koro Toro ended when Habré defeated Qaddafi in 1987.
The
Aozou Strip (alternatively, Aouzou Strip) is a strip of land in northern Chad which lies along the border with Libya, extending south to a depth of about 100 kilometers into Chad's Bourkou-Ennedi-Tibesti prefecture.
Claimed to be rich with uranium deposits, a dispute over the control of this area with Libya led to a war between the two countries. In 1973, Libya engaged in military operations in the Aozou Strip to gain access to minerals and to use it as a base of influence in Chadian politics. Libya argued that the territory was inhabited by indigenous people who owed allegience to the Senoussi Order and subsequently to the Ottoman Empire, and that this title had been inherited by Libya. It also supported its claim with an unratified 1935 treaty between France and Italy, the colonial powers of Chad and Libya, respectively. After consolidating its hold on the strip, Libya annexed it in 1976.
The frontier claimed by the Chadian government was based on a 1955 treaty between France and Libya, which, in turn, referred back to an 1899 agreement between Great Britain and France about "spheres of influence". Despite other differences, this was one position on which all Chadian political parties and factions were able to agree.
Chadian forces were able to force the Libyans to retreat from the Aozou Strip in 1987. A cease-fire between Chad and Libya held from 1987 to 1988, followed by unsuccessful negotiations over the next several years, leading finally to the 1994 International Court of Justice decision granting Chad sovereignty over the Aozou strip, which ended Libyan occupation.