Fallout's Creator Unravels Long-standing Mystery

TL;DR
Tim Cain, one of the creators of the Fallout franchise, revealed in an interview that the reason the game's world is a radioactive wasteland is because China discovered that the U.S. was conducting illegal bioweapons research involving the Forced Evolutionary Virus (FEV). In retaliation, China launched nuclear weapons, resulting in the fallout that created mutated and hostile species in the U.S. This revelation solves one of the biggest mysteries in the Fallout franchise, but there are still many more unanswered questions.
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