When Somalia invaded Ethiopia in July 1977 in the Ogaden War, the Cold War played a role. The Soviets, who traditionally backed Somalia, now switched to support of the Marxist regime in Ethiopia. The United States remained neutral because Somalia was clearly the aggressor nation, and in 1978 with the assistance of 20,000 Cuban troops, Ethiopia defeated Somalia. The most important American success was helping the transition from white-dominated Southern Rhodesia to black rule in Zimbabwe. The United States supported UN resolutions and sanctions that proved effective in April 1980. Despite human rights concerns, Carter continued U.S. support for Joseph Mobutu of Zaire, who defeated Angolan-backed insurgents in conflicts known as Shaba I and Shaba II.