The populations of eastern Chad and western Sudan established social and religious ties long before either nation's independence, and these remained strong despite disputes between governments.

[1] In recent times, relations have been strained due to the conflict in Darfur and a civil war in Chad, which both governments accuse the other of supporting.

[1] At the same time, the basis for political enmity between these two nations was set in the early 1960s, when Chad's southern bias in government offended many Sudanese Muslims.

[1] At the time of the Bashir coup in June 1989, western Darfur was being used as a battleground by troops loyal to the Chadian government of Hissène Habré and rebels organized by Idriss Déby and supported by Libya.

[2] The RCC-NS was not prepared for a confrontation with Chad, which was already providing assistance to the SPLM, and thus tended to turn a blind eye when Chadian forces crossed into Darfur in pursuit of the rebels.

Deby's Patriotic Movement for Salvation (Mouvement Patriotique du Salut) provided arms to Sudanese Zaghawa and Arab militias, ostensibly so that they could protect themselves from Chadian forces.

[3] Chadian president Idriss Déby, a Zaghawa who came from the Sudan border area, worked hard but without success to mediate an end to the dispute between the government in Khartoum and the Darfur rebel groups.

[3] Following deadly clashes along the Sudan–Chad border in April 2007, Chad's foreign minister said it was time to turn the page and improve relations with Sudan.

[4] On May 11, 2008, Sudan announced it was cutting diplomatic relations with Chad, claiming that it was helping rebels in Darfur to attack the Sudanese capital Khartoum.

[citation needed] Further efforts by both Libya and Qatar to improve relations between the two produced a security agreement in late 2009 to control rebel movements from Chad into Sudan.

[3] The first fruit of these developments was a framework agreement between Khartoum and the main JEM rebel group, signed in N’djamena on February 20, providing for a cease-fire and for further negotiations in Doha, Qatar.

The resulting deal saw Chad kick out the Darfuri Justice and Equality Movement rebels it had previously supported, dramatically changing the Darfur dynamic.