Back in 2002, Meles Zenawi, then prime minister of Ethiopia, drafted a foreign policy and national security white paper for his country. Before finalizing it, he confided to me a “nightmare scenario” — not included in the published version — that could upend the balance of power in the Horn of Africa region.

The scenario went like this: Sudan is partitioned into a volatile south and an embittered north. The south becomes a sinkhole of instability, while the north is drawn into the Arab orbit. Meanwhile, Egypt awakens from its decades-long torpor on African issues and resumes its historical stance of attempting to undermine Ethiopia, with which it has a long-standing dispute over control of the Nile River. It does so by trying to bring Eritrea and Somalia into its sphere of influence, thereby isolating the government in Addis Ababa from its direct neighbors. Finally, Saudi Arabia begins directing its vast financial resources to support Ethiopia’s rivals and sponsor Wahhabi groups that challenge the traditionally dominant Sufis in the region, generating conflict and breeding militancy within the Muslim communities.