Letter from D. Arkell, Defense Intelligence Staff, to R. J. T. McLaren, Eastern Department of the Foreign Office

After analyzing photographs taken of the Israeli nuclear facility at Dimona, J. Koop, a career intelligence analyst at Canada's Defence Research Board, concluded in March 1964 that Dimona had all of the "prerequisites for commencing a modest nuclear weapons development project." When the Dimona reactor went critical, it could produce enough plutonium for at least one implosion device by the end of 1965 and increase its operating level to produce one to two per year by 1966. Arthur Kellas, a British diplomat in Israel, wrote in his forwarding letter that they were highly impressed by the analysis.

Noting some inaccuracy in the Canadian Defence Research Board report---Argentina could not have offered to sell its “entire production” of uranium if it was also selling concentrate to Germany and trying to sell it to Japan—Goodison, of the Foreign Office's Eastern Department, asked Audland, a political officer at the British Embassy in Buenos Aires, to “keep your ears to the ground” to find the “exact quantities” involved.