Could someone give me a brief rundown of East African communism?

The Derg, the Isaaq Genocide, the Ogaden war, the Somali Democratic Republic.​How do these events relate? What's the backstory? What role did the USSR play? I know events and names, but I don't know the actual history of communist governments in East Africa via /r/communism https://ift.tt/3mb2v1J