HAVANA – The world stood at the brink of Armageddon for 13 days in October 1962 when President John F. Kennedy drew a symbolic line in the Atlantic and warned of dire consequences if Soviet Premier Nikita Khrushchev dared to cross it.

An American U-2 spy plane flying high over Cuba had snapped aerial photographs of Soviet ballistic missile sites that could launch nuclear warheads with little warning at the United States, just 90 miles away. It was the height of the Cold War, and many people feared nuclear war would annihilate human civilization.

Soviet ships carrying nuclear equipment steamed toward Kennedy’s “quarantine” zone around the island, but turned around before reaching the line.