@High Seas,
Well, the Libyans, even before Got-Daffy took over, tried for many years to exploit the relative kinship (i wouldn't call it close--either you're in my tribe or you're not) with the people of northern Chad. Those people i suspect thought that they could free themselves from the government in the south, and then show the Libyans the door, and live free and easy--a naïve assumption to put it in the kindest of terms.
But from the 1950s onward, and regularly and more intensively after Got-Daffy took over in 1969, the Libyans would venture into northern Chad, only to be turned back by the tiny Chadean army, supported by French air power. By the late 1970s, the French were refusing to commit any resources north of a certain line, but it didn't do the Libyans any good. At first, in the 1980s, they couldn't make any headway, and then in the Toyota war in 1989, the "loyal" Chadean forces handed them their military ass, and did it without French intervention. Noting these things, and especially that the tribes in northern Chad provided the Libyans a base from which to operate, only makes the Libyan military and Got-Daffy look all the more pathetic.