This paper is a review of peace and security in the Horn of Africa and the role of Ethiopia in peace operation in the region. The analysis presented in the article is based on the qualitative data provided by international organizations, governments, research institutions and other concerned bodies. The paper is developed with the use of a historical method, as well as discourse analysis of the literature on the subject, official documents and the press. In the contemporary world politics Regional security Complexes play an important role in sponsoring Peace and stability. Ethiopia is a key ally of the Western world, especially the U.S., which considers it as an important regional security partner in the global war on terror, and recently as negotiators in conflict resolution stages in most of Horn of African states. Undoubtedly, Ethiopia plays a key role in the security complex of the Horn of Africa. Ethiopia, which is located at geographically strategic place, and the most populous country in the region, enjoys relative power among the countries in this region. Regardless of the external and internal problems, Ethiopia's position is growing from time to time, just as its economic and political potential developed. In the region itself, no country doubt Ethiopia’s leading role and compete for hegemony in the Horn of Africa, which is because of the magnitude of Ethiopian economy and its rich history. It means the historic legacy/link with almost all of the horn countries levy Ethiopia a burden as well as privilege on Ethiopia in patrolling the region.

Keywords: Ethiopia, Horn of Africa, regional security. Security Complex,