Both past Ethiopian leaders Emperor Haile Selassie and Colonel Mengistu Hailemariam supported the separatist Sudan People's Liberation Movement (SPLM) against the central government of Sudan. Now decades later, the SPLM is in full control of southern Sudan and its people are voting in a referendum for independence.

There are some positives and negatives for Ethiopia in regards to the Southern Sudan situation. An independent Southern Sudan could give Ethiopia a new economic partner, a friendly neighbor and a better future alternative for a source of energy (oil). Southern Sudan is also likely to support Ethiopia in its case for a bigger share of the Nile river against Egypt. However, South Sudan's secession can open up new sources of border dispute for Ethiopia as well. Several anti-government groups can also find a new home in Juba, the capital city of Southern Sudan. If current and future Ethiopian governments can not balance their relations between Juba and Khartoum, rebels could use the new country as a base.

A potential border war between Juba and Khartoum could worsen the refugee situation in western Ethiopia as well.

This week's referendum also provides a political and moral support for armed groups in the region. ONLF rebels of Ethiopia have already praised the referendum in Sudan. In a statement, the ONLF said

"This vote represents a precedent affirming that there is no longer a moral or so-called legal basis for denying the Ogaden people their legitimate rights to self-determination and that the AU bears a direct responsibility to address protracted conflicts."

Some analysts say the Eritrean and Southern Sudan cases encourage other regional African separatists to continue armed struggle. In addition to the ONLF, the other notable armed group in Ethiopia is the Oromo Liberation Front (OLF). However, there are no more regional separatist movements left in Ethiopia. Both the Ogaden and Oromia based separatist movements in Ethiopia are ethnic or clan based in contrast to the multi-ethnic and multi-religious regions of Eritrea and Southern Sudan.

Still, Southern Sudan provides a secular alternative for pro-democracy opposition movements in Ethiopia who want to fight from a western base in a neighboring country. Particularly, dissidents in the Gambella region of western Ethiopia could become emboldened. With many advantages and disadvantages, it is uncertain whether Southern Sudan's secession benefits Ethiopia or not.