At the height of the Cold War, America's greatest agent known as The Boss defects to the Soviet Union. At the same time, an extremist named Colonel Volgin fires an American-made portable nuclear missile at the Soviet design bureau OKB-754, sparking an international incident. In order for America to clear its name and avoid World War III, a man named John and codenamed Naked Snake is dispatched by the special forces unit FOX to assassinate the woman who taught him everything.