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.

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.

[20] 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".

[23][24] Good relations were confirmed in the following years, with Gaddafi visiting the Chadian capital N'Djamena in March 1974;[25] in the same month a joint bank was created to provide Chad with investment funds.

[13] In April 1976, there was a Gaddafi-backed attempted assassination of Malloum,[23] and in the same year, Libyan troops started making forays into central Chad in the company of FROLINAT forces.

The insurgents split on the issue of Libyan support in October 1976, with a minority leaving the militia and forming the Armed Forces of the North (FAN), led by the anti-Libyan Hissène Habré.

For the first time with the active participation of Libyan ground units,[14] Goukouni's FAP unleashed the Ibrahim Abatcha offensive on 29 January 1978 against the last outposts held by the government in northern Chad: Faya-Largeau, Fada and Ounianga Kébir.

[35] Malloum and Gaddafi restored diplomatic relations on 24 February 1978 in Sabha, Libya, where an international peace conference was held which included as mediators Niger's president, Seyni Kountché, and Sudan's vice-president, Abu al-Gasim Mohamed Ibrahim.

[35] The stillborn accord was for Gaddafi nothing more than a strategy to strengthen his protégé Oueddei; it also weakened considerably Malloum's prestige among southern Chadians, who saw his concessions as a proof of his weak leadership.

Already in 1977, after Oueddei's first offensives, Malloum had asked for a French military return in Chad, but President Valéry Giscard d'Estaing was at first reluctant to commit himself before the 1978 legislative elections; also, France was afraid of damaging its profitable commercial and diplomatic relations with Libya.

In particular, Goukouni and his men had shown themselves reluctant to follow Gaddafi's solicitations to make The Green Book the official policy of the FROLINAT, and had first tried to take time, postponing the question until the complete reunification of the movement.

When the unification was accomplished, and Gaddafi pressed again for the adoption of The Green Book, the dissensions in the Revolution's Council became manifest, with many proclaiming their loyalty to the movement's original platform approved in 1966 when Ibrahim Abatcha was made first secretary-general, while others, including Acyl, fully embraced the Colonel's ideas.

In the same month, the factions excluded by the GUNT founded a counter-government, the Front for Joint Provisional Action (FACP), in northern Chad with Libyan military support.

[58][59] While the FAN was supplied economically and militarily by Sudan and Egypt, Goukouni received the armed support of Kamougué's FAT and Acyl's CDR shortly after the beginning of the battle and was provided with Libyan artillery.

[59][60] Beginning in October, Libyan troops, led by Khalifa Haftar and Ahmed Oun, airlifted to the Aouzou Strip operated in conjunction with Goukouni's forces to reoccupy Faya.

These forces created considerable annoyance in the GUNT by supporting Acyl's faction in its disputes with the other militias, including the clashes held in late April with Goukouni's FAP.

Before the peace-keeping force was fully deployed, Habré had already taken advantage of Libya's withdrawal and made massive inroads in eastern Chad, including the important city of Abéché, which fell on 19 November.

Two days later Habré entered N'Djamena unopposed, making him the de facto leader of Chad, while Goukouni fled the country, seeking sanctuary in Cameroon.

[76] Since Gaddafi had kept mostly aloof in the months before the fall of N'Djamena, Habré hoped to reach an understanding with Libya, possibly through an accord with Acyl, who appeared receptive to dialogue.

For the impending fight, Goukouni could count on 3,000–4,000 men taken from several militias, later merged in an Armée Nationale de Libération (ANL) under the command of a Southerner, Negue Djogo.

Gaddafi suffered also a diplomatic setback from the OAU, that at the meeting held in June officially recognized Habré's government and asked for all foreign troops to leave Chad.

Habré crushed Goukouni's forces and started a vast counteroffensive that enabled him to retake in rapid succession Abéché, Biltine, Fada and, on 30 July, Faya-Largeau, threatening to attack the Tibesti and the Aouzou Strip.

Within ten days, a large ground force had been assembled east and west of Faya-Largeau by first ferrying men, armor, and artillery by air to Sabha, Kufra and the Aouzou airfield, and then by shorter-range transport planes to the area of conflict.

Mengistu's failure was followed on 24 January 1984 by a GUNT attack, supported by heavy Libyan armor, on the FANT outpost of Ziguey, a move mainly meant to persuade France and the African states to reopen negotiations.

Also decisive was the increasing factional bickering that started plaguing the GUNT since 1984, centered around the fight between Goukouni and Acheikh ibn Oumar over the organization's leadership.

[95] In this period, Gaddafi expanded his control over northern Chad, building new roads and erecting a major new airbase, Ouadi Doum, meant to better support air and ground operations beyond the Aouzou Strip.

[7] On the other side, the FANT was greatly strengthened, now having 10,000 highly motivated troops, provided with fast-moving and sand-adapted Toyota trucks equipped with MILAN anti-tank missiles.

This strategy was repeated by Djamous in March in the battles of B'ir Kora and Ouadi Doum, inflicting crushing losses and forcing Gaddafi to evacuate northern Chad.

In May 1988, the Libyan leader declared he would recognize Habré as the legitimate president of Chad "as a gift to Africa" which led on 3 October 1988 to the resumption of full diplomatic relations between the two countries.

The following year, on 31 August 1989, Chadian and Libyan representatives met in Algiers to negotiate the Framework Agreement on the Peaceful Settlement of the Territorial Dispute, by which Gaddafi agreed to discuss with Habré the Aouzou Strip and to bring the issue to the ICJ for a binding ruling if bilateral talks failed.