The Uganda–Tanzania War of 1978–1979 has received little attention from historians. This article uses British diplomatic sources to explore the causes and course of the conflict. In particular, it examines how Tanzanian President Julius Nyerere sought to hide from and later justify to the rest of the world an invasion of Uganda and the overthrowing of Idi Amin, actions that contravened the Charter of the Organisation of African Unity (OAU). Distinct among contemporaneous African conflicts for its noticeable lack of a Cold War context, the war demonstrated the shortcomings of the OAU in resolving African conflicts. Despite some dissenting voices, Nyerere's own disregard for state sovereignty was largely overlooked, as the fall of Amin's regime was quietly welcomed by the majority of Africa's leaders.