February 19, 1960
A.A. Wells, Director, Division of International Affairs, to Philip J. Farley, Special Assistant to the Secretary of State for Disarmament and Atomic Energy, 'Control of and Cooperation in Gas Centrifuge Research and Development Program'
The development of the gas centrifuge method, according to this report, would make production of U-235 (and by extension, nuclear weapons) possible for as many as 20-30 foreign countries. The U.S. is thus forced to consider its strategy for how to limit proliferation despite this new, cheap technology.
March 23, 1960
Philip J. Farley, special Assistant to the Secretary of State, to Algie A. Wells, Director, Division of International Affairs, Atomic Energy Commission, 'Control of and Cooperation in Gas Centrifuge Research and Development Program'
As West Germany and The Netherlands developed ultra-centrifuges without a classification policy, the AEC discuss ways to keep the technology under wraps without arousing suspicion from the other members of Euratom.
April 10, 1961
Department of State Memorandum of Conversation, 'U.S. Visit to Dimona Reactor Site'
Ambassador Harman informs Jones and Philip Farley, the special assistant to the secretary of state for atomic energy and outer space matters, that Israel is formally inviting a US scientist to visit the Dimona complex during the week of 15 May, but that the visit should be secret.