Documents uncovered by Newsnight in the British National Archives show how, in 1958, Britain agreed to sell Israel 20 tonnes of heavy water, a vital ingredient for the production of plutonium at Israel's top secret Dimona nuclear reactor in the Negev desert.
Robert McNamara, President John F Kennedy's defence secretary, has told Newsnight he is 'astonished' at the revelation that Britain kept this secret from America.
"I think it is quite extraordinary," says the former Conservative Defence and Foreign Office minister Lord Gilmour. "Whether the civil servants who were involved knew what they were doing, or whether they didn't, I don't know." He thinks they put Britain's economic interests first.
"One must assume they must have known... And what's more they seemed to have no idea of the political or indeed even the technical and foreign-policy implications of what they were doing. They just seemed to be concerned with making a bit of money."
According to the Newsnight report, all this was sanctioned by relatively low-level civil servants without ever crossing the path of cabinet ministers.
The Antagonist is not entirely sure whether the attribution to low level civil servants for this deed is more worrying than attribution to tacit approval within the government, at the least within the Foreign Office.
Either way, another clear demonstration of the hidden hand of government at work again.