Cuban and Ethiopian troops quickly defeated the SNA and WSLF once the counteroffensive began. Many WSLF fighters returned to their villages or took refuge inside Somalia. In addition, some 650,000 Somali and Oromo fled from southeastern Ethiopia into Somalia by early 1978 to escape unsettled local conditions and repression by Ethiopian armed forces. After the defeat, Somali opposition reverted to sporadic guerrilla ambushes and occasional acts of sabotage.

On April 4, 1988, after several preparatory meetings, Ethiopia and Somalia signed a joint communiqué that supposedly ended the Ogaden conflict. According to the communiqué's terms, the two countries committed themselves to withdrawing their military forces fifteen kilometers from the border, exchanging prisoners of war, restoring diplomatic relations, and refraining from supporting each other's antigovernment guerrilla groups. Reportedly, a separate secretaccord contained a Somali renunciation of all claims to the Ogaden region. From Mengistu's point of view, the joint communiqué secured Ethiopia's southeastern border, thereby enabling Addis Ababa to devote more resources to the struggle against the EPLF and TPLF in northern Ethiopia.

Nevertheless, by 1991 it had become evident that Ethiopia had failed to honor the provisions of the joint communiqué. The Mengistu regime allowed the anti-Siad Barre Somali National Movement (SNM) to maintain offices in Addis Ababa and Dire Dawa and to operate five training camps near Dire Dawa. Additionally, the Ethiopian government still provided matériel and logistical support to the SNM. Despite these violations, Somalia refrained from reinitiating hostilities with Ethiopia.

Relations between Ethiopia and Sudan were generally good until the mid-1980s, when the Sudanese People's Liberation