In a new book Command and Control, journalist Eric Schlosser chronicles America's terrifying nuclear mishaps and near misses.

He recounts how in one incident in 1961, days after President John F Kennedy's inauguration, two hydrogen bombs were accidentally dropped on Goldsboro, North Carolina, as a B-52 bomber went into a tailspin.

Only the failure of a single low-voltage switch prevented disaster, Schlosser explains to the BBC's Katty Kay.

"The bomb assumed it was being deliberately released over an enemy target - and went through all its arming mechanisms save one, and very nearly detonated over North Carolina," said Schlosser.

"And Robert McNamara had just become secretary of defence and he was terrified by this news. We nearly had a hydrogen bomb detonate a few days after JFK's inauguration that would have changed literally the course of history."