‘Humphrey’s enthusiasm for Trident knows no bounds. ‘But don’t you see Prime Minister – with Trident we could obliterate the whole of Eastern Europe.’
I don’t want to obliterate the whole of Eastern Europe. I told him so. He nodded impatiently. He knew that. He thought I was missing the point. ‘It has to be an effective deterrent, Prime Minister.’
‘But it’s a bluff,’ I told him, ‘I probably wouldn’t use it.’
‘They don’t know that you probably wouldn’t use it,’ he argued.
‘They probably do,’ I said.
He was forced to agree. ‘Yes… they probably know that you probably wouldn’t. But they can’t certainly know.
He’s right about that. But they don’t have the certainty to know. ‘They probably certainly know that I probably wouldn’t,’ I said.
‘Yes,’ he agreed, ‘but even though they probably certainly know that you probably wouldn’t, they don’t certainly know that although you probably wouldn’t, there is no probability that you certainly would.’
Bernard was taking careful minutes. It’s lucky he does shorthand and was able to reconstruct this conversation for me in writing by the end of the day.’
– Lynn J., Jay A. 1986. The Complete Yes Prime Minister London, Great Britain: BBC Books (1989) p. 79-80