There are many names for whatever happened in the South Atlantic on Sept. 22, 1979, but the most typical one is "the Vela Incident." It is one of the genuine mysteries of 20th-century history - not a contrived mystery like "Who killed the Lindbergh baby?", but the real deal: a whodunit, combined with a whatwuzzit. At just past midnight on the key date, an American satellite designed to detect nuclear explosions, Vela 6911, "announced" to ground stations that it was pretty sure it had just seen one.
The inferred location of the blast was about halfway between South Africa and Antarctica. This may not seem like an important clue to post-Cold War babies; people forget that South Africa is known to have had the bomb throughout the 1980s. The apartheid regime built a half-dozen warheads for tactical use and regional deterrence against such Communist-influenced neighbour states as Angola. In 1989, during the run-up to South African democracy, the republic voluntarily dismantled its nukes. Over the next decade it joined the major nonproliferation treaties, and even led the creation of a new one, the African Nuclear-Weapon-Free Zone Treaty.
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