ABSTRACT The Red Sea region has rapidly changed during the last decades due to growing foreign countries’ rivalry and military base expansion. This study examines foreign countries’ military base expansion and its implications for the Horn of Africa’s security. The study uses a qualitative research approach, collecting data from secondary sources. The study argues that foreign countries’ military base expansion in the Red Sea region has both advantages and disadvantages to the Horn of Africa region. Foreign military presence in the Red Sea region enables the region’s states to combat terrorism and piracy and has economic benefits and military experience sharing with host states. However, foreign military presence will exacerbate patronage, open avenues for interference in the internal affairs of states, and foreign countries competition complicates the security of the volatile Horn of Africa region. Hence, the Red Sea littoral states shall strengthen their cooperation to reduce the adverse effect of foreign countries’ military base expansion and enhance their political, economic, and diplomatic bargaining power.