The Chadian–Libyan War was a series of military campaigns in Chad between 1978 and 1987, fought between Libyan and allied Chadian forces against Chadian groups supported by France, with the occasional involvement of other foreign countries and factions.
Libya had been involved in Chad's internal affairs prior to 1978 and before Muammar Gaddafi's rise to power in Libya in 1969, beginning with the extension of the Chadian Civil War to northern Chad in 1968. The conflict was marked by a series of four separate Libyan interventions in Chad, taking place in 1978, 1979, 1980–1981 and 1983–1987. On all of these occasions, Gaddafi had the support of a number of factions participating in the civil war, while Libya's opponents found the support of the French government, which intervened militarily to support the Chadian government in 1978, 1983 and 1986.
The pattern of the war delineated itself in 1978, with the Libyans providing armour, artillery and air support and their Chadian allies the infantry, which assumed the bulk of the scouting and fighting. This pattern was radically changed in 1986, towards the end of the war, when most Chadian forces united in opposing the Libyan occupation of northern Chad with a degree of unity that had never been seen before in Chad. This deprived the Libyan forces of their habitual infantry, exactly when they found themselves confronting a mobile army, well provided now by the United States, Zaire and France with anti-tank and anti-air missiles, thus cancelling the Libyan superiority in firepower. What followed was the Toyota War, in which the Libyan forces were routed and expelled from Chad, putting an end to the conflict.
Gaddafi initially intended to annex the Aouzou Strip, the northernmost part of Chad, which he claimed as part of Libya on the grounds of an unratified treaty of the colonial period. In 1972 his goals became, in the evaluation of historian Mario Azevedo, the creation of a client state in Libya's "underbelly", an Islamic republic modelled after his Jamahiriya, that would maintain close ties with Libya, and secure his control over the Aouzou Strip; expulsion of the French from the region; and use of Chad as a base to expand his influence in Central Africa.
Background
Occupation of the Aouzou Strip
Libyan involvement with Chad can be said to have started in 1968, during the Chadian Civil War, when the insurgent Muslim National Liberation Front of Chad (FROLINAT) extended its guerrilla war against the Christian President François Tombalbaye to the northerly Borkou-Ennedi-Tibesti Prefecture (BET). Libya's king Idris I felt compelled to support the FROLINAT because of long-standing strong links between the two sides of the Chad–Libya border. To preserve relations with Chad's former colonial master and current protector, France, Idris limited himself to granting the rebels sanctuary in Libyan territory and to providing only non-lethal supplies.
All this changed with the Libyan coup d'état of 1 September 1969 that deposed Idris and brought Muammar Gaddafi to power. Gaddafi claimed the Aouzou Strip in northern Chad, referring to an unratified treaty signed in 1935 by Italy and France (then the colonial powers of Libya and Chad, respectively). Such claims had been previously made when in 1954 Idris had tried to occupy Aouzou, but his troops were repelled by the French Colonial Forces.
Though initially wary of the FROLINAT, Gaddafi had come to see by 1970 the organization as useful to his needs. With the support of Soviet bloc nations, particularly East Germany, he trained and armed the insurgents, and provided them with weapons and funding. On 27 August 1971 Chad accused Egypt and Libya of backing a coup against then-president François Tombalbaye by recently amnestied Chadians.
On the day of the failed coup, Tombalbaye cut all diplomatic relations with Libya and Egypt, and invited all Libyan opposition groups to base themselves in Chad, and started laying claims to Fezzan on the grounds of "historical rights". Gaddafi's answer was to officially recognize on 17 September the FROLINAT as the sole legitimate government of Chad. In October, Chadian Foreign Minister Baba Hassan denounced Libya's "expansionist ideas" at the United Nations.