“Projections about the nation’s fate in the event of war – and no one supposed for a moment that the UK might be spared, if the Soviet Union attacked the US – were then based on 1955 estimates that ten 10-megaton H-bombs would kill twelve million of the country’s forty-six million people, and incapacitate many more. A later 1964 estimate would have been more realistic: A Soviet attack, this stated, ‘would cause the United Kingdom to cease to exist as a corporate political entity’.”