Ethiopia, situated at the heart of the volatile Horn of Africa, has long found itself in various conflicts that have ravaged the region. Among them is its 2006 war with the Union of Islamic Courts (UIC) inside Somalia in support of the country’s weak Transitional Federal Government (TFG). It was a major projection of power by an African state in another country that ended up with Ethiopia’s ‘occupation’ of Somalia for the next two years. Nonetheless, the nature of the threat, the scale of the military operation, the justifications given to it and the context in which it was conducted show that it would have been unlikely to fight the war had Ethiopia been a democracy. Despite the conduct of periodic elections since the current EPRDF regime militarily took power in 1991, its rule has been characterized as authoritarian. This thesis accordingly tries to make sense of the war from the prism of Ethiopia’s domestic political system by attempting to answer the research question: how did authoritarianism lead Ethiopia to the 2006 war in Somalia? Guided by eclectically synthesized analytical framework on democratic constraints and authoritarian triggers of conflict, the thesis identifies four major mechanisms as a set of answers to the research question: a) by serving as the genesis of the threat; b) limiting the capacity of the regime to accurately assess the magnitude of the threat and the capabilities and commitments of its allies; c) increasing the gains of fighting the war to the regime, whose interest is fused with the national interest; and d) eliminating the institutional constraints and audience costs of fighting the war.