The East African Community has one of the most vibrant and dedicated collective security arrangements in Sub-Saharan Africa. In recent times, the consistency with which terrorist organizations have targeted the region has necessitated collective security mechanisms to help address the menace and guarantee stability in the economically strong region. The region is threatened by growing youth radicalization and other security threats emanating from poverty, high unemployment, political violence, weak democratic structures, boundary disputes, bad governance and unfair distribution of resources. Having a history of cooperation, collective security has not been an issue in the region. The East African Community has a lengthy history of existence since the independence years of the three founding members namely; Kenya, Uganda, and Tanzania, though the community has faced numerous disagreements. Collective security in East Africa has focused on addressing major security challenges but it is likely going to expand to address terrorism. The weaknesses in the implementation of collective security in the region is mainly contributed by lack of political will, resistance to perceived western influence, poor leadership, lack of institutional capacity, lack of funds and the unpredictable nature of security challenges. Therefore, states in the region come together and strengthen their resolve to tackle security problems. To achieve this, building closer ties within the region and increased investment in defence and security are necessary.