 The war began with the Libyan occupation of northern Chad in 1983 , when Libya 's leader Muammar Gaddafi , refusing to recognize the legitimacy of the Chadian President Hissène Habré , militarily supported the attempt by the opposition Transitional Government of National Unity ( GUNT ) to overthrow Habré . The plan was foiled by the intervention of France which , first with Operation Manta and later with Operation Epervier , limited Libyan expansion to north of the 16th parallel , in the most arid and sparsely inhabited part of Chad . 
