...Somalia's unwillingness to recognize political boundaries drawn by British, French, and Italian colonists, in conjunction with Ethiopia. Since independence, successive Somali governments had sought to reincorporate those Somalis living in Ethiopia, Kenya, and Djibouti into Greater Somalia. (Under the Siad Barre regime, the five-pointed star on the Somali flag represented the northern and southern regions of the republic and the "unredeemed territories" in Kenya's North-Eastern Province, Ethiopia's Ogaden Province, and Djibouti.) In 1960-64, for example, guerrillas supported by the Somali government battled local security forces in Kenya and Ethiopia on behalf of Somalia's territorial claims. Then, in 1964, Ethiopian and Somali regular forces clashed.
By late 1964, it had become obvious that the initial campaign to unify all Somalis had failed. Ethiopian forces had established superiority over the Somalis in the Ogaden, in part because of Ethiopia's ability to conduct air raids on Somali territory. In Kenya the government relied on assistance from British counterinsurgency experts to control Somali guerrillas in what was then the Northern Frontier District (NFD). In late 1964, Kenya's president Jomo Kenyatta and Ethiopia's emperor Haile Selassie signed a mutual defense agreement aimed at containing Somali aggression. The two countries renewed the pact in 1979 and again in 1989. These factors, in combination with the opposition of the Organization of African Unity to Somali aims and defense costs that amounted to 30 percent of the national budget in the mid-1980s, forced Mogadishu to reconsider its territorial ambitions.