This episode of the M.A.D. World series tracks the Cold War's most volatile stretch as the nuclear arms race spirals and proxy wars spread across continents. Chile's elected Marxist government falls to a military coup with CIA fingerprints on it, American troops leave Vietnam as Saigon falls, and Angola becomes a new kind of battlefield where Soviet and American weapons arrive alongside mercenaries after Portugal's colonizers withdraw. Arms talks stall over Soviet tanks in Europe and American nuclear weapons in West Germany, while superpowers keep stockpiling ever more sophisticated warheads. The chilling centerpiece is Nevada's test of the neutron bomb, a weapon engineered to kill people with radiation while sparing buildings, which draws global headlines and mass anti-nuclear protests. The episode closes with Jimmy Carter and Leonid Brezhnev meeting in Vienna to sign a treaty capping each side's nuclear arsenal at 2,400 systems. Archival footage and narration move briskly between these fronts, showing how a single decade's crises fed the logic of mutually assured destruction.