Kenya, however, had been consistently rejected by the UN, the OAU, and most of the world's sovereign states. Still, Somalia's leadership remained unwilling to forsake these claims publicly.

In 1961, less than a year after Somalia gained independence, its troops clashed with Ethiopian soldiers along their common border. In 1964 renewed tensions erupted into a minor regional war. In both cases, Somalia was defeated. Ethnic Somali in Kenya's northeast also unsuccessfully challenged that country's new government in the early 1960s. Pan-Somalism, then, served as a basis for the continuance of cooperative relations between Nairobi and Addis Ababa, despite the change of regime in Ethiopia. The two countries first signed a mutual defense agreement in 1964 that resulted in the creation of the Ethiopia-Kenya Border Administration Commission.

The Ogaden War (1977-78)was the most serious border conflict between Ethiopia and Somalia. Beginning in the early summer of 1977, SNA units and WSLF guerrillas, a movement of ethnic Somali opposed to incorporation in Ethiopia, occupied vast tracts of the Ogaden and forced the Ethiopian army into fortresses at Jijiga, Harer, and Dire Dawa for almost eight months. The intention was to separate the Ogaden from Ethiopia to set the stage for ethnic Somali in the region to decide their own future.

It was only with Soviet and Cuban assistance that the Derg regained control over the region by early 1978. The Soviet Union not only provided massive amounts of military equipment but also advisers, who trained Ethiopian soldiers and pilots. Moreover, Cuban troops spearheaded the counteroffensive that began in March 1978.