By the close of 1987, Chad had experienced conditions of chronic warfare for twenty-two years. During the first fourteen years of this period (1965-79), Muslims of the north and central regions had pursued a guerrilla campaign against the central government, which was dominated by non-Muslim, French-speaking southerners. The military occupation of N'Djamena by northern insurgents in 1979 was an important turning point. Although the struggle continued with increasing severity, its shape now changed. Differences between north and south persisted but had become secondary to the developing conflict between the two northern rivals--Habré and Goukouni. Habré's skills as a military commander repeatedly enabled him to prevail against domestic military opponents. He could not withstand, however, the combined onslaught of the forces of Goukouni and his Libyan collaborators when Qadhaafi interceded in strength in 1980 and again in 1983.
French troops returned to Chad in 1983 to block the southward advance of the Libyans, imposing a de facto cease-fire and partition of the country. The south and central regions were controlled by Habré, protected by a French line of defense, and the north was occupied by the armies of Goukouni shielded by Libyan ground and air power.
In the late summer of 1986, the balance of military power shifted when most of the troops of Goukouni's coalition rebelled against their Libyan allies. Isolated and demoralized, the Libyans were driven from their Chadian bases in a series of stunning blows by Habré's army in the early months of 1987. The conflict had been transformed from a civil war, in which Libya was backing one of the claimants to authority in Chad, into a national crusade by a virtually united Chad to drive Libyan forces from its territory.
Data as of December 1988