Only one country who developed nuclear weapons ever gave them up

In 1979, American Vela Hotel satellites detected a bright double flash near the Prince Edward Islands of Antarctica. A double-flash is a clear indication of a nuclear explosion in the atmosphere, as all 41 of the previous double flashes turned out to be. The only thing was this time, no one was claiming this unannounced nuclear test.

A Soviet spy later announced the flashes were caused by a joint Israeli-South African nuclear test.

The South Africans had been researching atomic energy since at least 1965, with the delivery of a U.S.-made nuclear research reactor and a supply of highly enriched uranium fuel. The country soon began to pour its resources into its own uranium enrichment programs and by 1969, was able to produce weapons-grade uranium on its own. By the 1970s, South Africa was developing nuclear explosions for use in mining, but that program quickly became a weapons development program. By the 1980s, South Africa was a nuclear weapons state.

In the 1980s, South Africa was also developing missiles that could be used with the six warheads they constructed, based on the Israeli designs for its Shavit rockets.

Israel's Shavit rockets delivers satellites into space for the Jewish state.

It's important to note that during this entire process, South Africa was fighting a prolonged border insurrection with its breakaway state of South West Africa and its allies in Angola and Cuba. Between 1966 and 1989, the Cold War raged hot in the southern tip of the continent as the South West African People's Organisation wrested control of the region against the South African Defence Forces. At the same time, the South Africans were fighting Angolan and Cuban intervention, as well as insurgent groups from nearby Zambia, especially the People's Liberation Army of Namibia.

The extended fighting at their borders gave South Africa a big incentive to develop nuclear weapons to bring leverage to their position at the negotiating table. When the Western powers and the Soviet Union got wind of potential South African nuclear tests in the late 80s, they were horrified and pressured the South Africans to abort the test. But South Africa never had any intention of putting warheads on the missiles; they didn't fit anyway. South Africa wanted the world to think they did, however.

A South African armored column in Ohangwena, Ovamboland in the 1970s.

Instead, the South Africans did the opposite. They signed a peace accord with all the belligerents they had been fighting for more than 20 years, withdrew their troops from South West Africa, and allowed the region to declare its independence as the new country of Namibia. The very next year, South Africa ended its nuclear program. Since then, it helped establish the African Nuclear-Weapon-Free Zone and became party to the Comprehensive Nuclear-Test-Ban Treaty, ending more than 40 years of nuclear weapons research.