Before the words “nuclear nonproliferation” entered official discourse, the term “non-diffusion” (or “non-dissemination”) of nuclear weapons was used routinely. In part stemming from the negotiations over Berlin, during 1962-1963 the Kennedy administration held talks with allies and adversaries on the possibility of a non-diffusion agreement which included Germany. In light of a recent Soviet proposal, INR veteran Soviet expert Sonnenfeldt explained why Moscow had moved away from earlier proposals singling out West Germany and was focusing on the general applicability of a non-diffusion agreement.

As discussion of a NATO multilateral force (MLF) unfolded, unfolded, one question which had to be addressed was how the Soviet Union would respond to the creation of such a NATO force. Because a NATO force would increase Western military capabilities, Soviet opposition was assumed.

This lengthy report was State Department Bureau of Intelligence and Research's contribution to the first National Intelligence Estimate on the nuclear proliferation, NIE 100-6-57. Written at a time when the United States, the Soviet Union, and the United Kingdom were the only nuclear weapons states, the “Fourth Country” problem referred to the probability that some unspecified country, whether France or China, was likely to be the next nuclear weapons state. Enclosed with letter from Helmut Sonnenfeldt, Division of Research for USSR and Western Europe, to Roger Mateson, 4 June 1957, Secret

Description of a meeting between Sonnenfeldt and Jean-Laurens Delpech, French Minister of Armaments. Delpech was concerned about the slow response to the French requests for further nuclear assistance. Sonnenfeldt explained that they were awaiting a detailed technical analysis of the requests and limitations of US policy. Delpech also raised the issues of French use of the Nevada Test Site. Attached to the memorandum is a handwritten letter by Delpech to National Security Advisor Brent Scowcroft.

Description of conversation between Sonnenfeldt and Jean-Laurens Delpech, French Minister of Armaments, on October 7. Delpech asked about the status of US nuclear assistance to France. He specifically asks about French requests for testing of reentry vehicle material in US nuclear tests, the importation of advanced computers, technical assistance with booster trigger design, and information on submarine vulnerabilities. Other topics included the French sale of helicopters to China and the potential sale of ECM equipment to Arab states.