In September 1962, British Defence Minister Peter Thorneycroft traveled to Washington for discussion on defense cooperation. During a flight with President Kennedy and Secretary of Defense McNamara, they discussed the French nuclear program and the possibility of French-German nuclear cooperation.

A collection of progress reports from the sub-commissions of the Accordo Military Tripartito F-I-G of 1957, a military alliance between Italy, France, and Germany, summarizing achievements and future objectives regarding development of co-owned nuclear weapons.

Ambassador Livingston Merchant, who was responsible for the U.S. diplomatic effort to win support for the MLF, asked INR to report on the degree to which non-nuclear European members of NATO were satisfied with their “lack of a share in ownership or control of nuclear weapons.” Based on the evidence, mainly various statements made by leading politicians, diplomats, and policymakers, INR experts concluded that most of the countries surveyed (Italy, Belgium, Netherlands, and Greece) were “relatively satisfied,” while only West Germany was “restive” to the extent that some of its officials were interested in a NATO or European nuclear force.

Concerns about the credibility of US nuclear deterrence generated Supreme Allied Commander Europe (SACEUR) General Lauris Norstad’s proposal for a NATO-controlled medium-range ballistic missile (MRBM) force. This lengthy report represented INR’s assessment of “present and future European interest in national or multinational nuclear weapons capabilities,” including the MRBM proposal, and the extent to which an “enhancement of NATO's nuclear role” could “deter national or multinational European nuclear weapons programs.”

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

This memo describes the details of the nuclear suppliers' conference, specifically the details of French participation. Cites the need for common understanding regarding nuclear exports is needed and therefore invites Great Britain, the Soviet Union, West Germany, Japan, and France to participate in the conference. Also details the process of trying to persuade France to participate and dissuading their reluctancy.

A secret report addressed to Minister of Foreign Affairs Mario Gibson Barbosa by Amb. Paulo Nogueira Batista (Brazilian Embassy, Bonn) describing alternatives for the establishment of comprehensive, long-term nuclear agreements between Brazil and a “country to be defined.” The report suggests that given the trends in uranium production in the US and Europe, Brazil needed to either associate itself with France to purchase gas diffusion technology or develop, together with Germany, ultracentrifugation or jet nozzle technologies. The notion was that “countries that decide to develop their own enrichment capacity will not only occupy a privileged competitive position but also will become part of an oligopoly with obvious political implications.” Nogueira Batista was worried, however, that Germany might not be able to offer Brazil centrifugation technology under existing obligations.

Edward Biegel of the Bureau of Western European Affairs answers Undersecretary Ball's questions on French nuclear ambitions and Western European collective security. He makes the arguments against nuclear sharing, and also mentions the fact that a Baltimore Sun article likely alerted the Soviets to the fact that the US deployed tactical nuclear weapons on the German front.

Sonnenfeldt summarizes various recent types of military cooperation between the United States and France. These include cooperation on contingency plans for dealing with Germany and US nuclear assistance to France. He suggests that it is time to define the "political philosophy underlying these disparate measures of cooperation."

President Kennedy writes British Prime Minister Harold Macmillan to discuss the implications for NATO and West German security if the US or UK assisted the French nuclear program.