May 31, 1957
Department of State Office of Intelligence Research, 'OIR Contribution to NIE 100-6-57: Nuclear Weapons Production by Fourth Countries – Likelihood and Consequences'
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
June 23, 1963
National Intelligence Estimate NIE 4-63, 'Likelihood and Consequences of a Proliferation of Nuclear Weapons Systems'
This NIE comes to the general conclusions that “there will not be a widespread proliferation of nuclear weapons over the next 10 years” and discusses programs in various countries (Israel, China, Sweden, India, West Germany, Japan, etc.) This copy includes newly declassified references to the Israeli nuclear weapons program, including the conclusion that “the Israelis, unless deterred by outside pressure, will attempt to produce a nuclear weapon some time in the next several years.”
August 28, 1963
Research Memorandum REU-56 from Thomas L. Hughes to the Secretary, 'Sweden Still Faces Question of Acquiring 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
April 23, 1964
Letter from Thomas Hughes, Director, Office of Intelligence and Research, Department of State, to Director of Central Intelligence John McCone
Noting new intelligence information on the Indian and Israeli nuclear programs, as well as the possibility of developments concerning Sweden, Hughes requested McCone to initiate a new estimate of nuclear proliferation trends, which would eventually become part of a October 1964 National Intelligence Estimate (NIE). Hughes enclosed draft “terms of reference,” that included questions about the possibility of “clandestine” weapons programs and new technological developments that could make weapons development “easier” (perhaps a reference to gas centrifuge technology that the 1964 NIE would discuss).
October 21, 1964
National Intelligence Estimate NIE 4-2-64, 'Prospects for a Proliferation of Nuclear Weapons Over the Next Decade'
This US analysis of the likelihood of nuclear proliferation during the next decade was finished only days after the first Chinese nuclear test on 16 October. The report analyses the implications of this test, as well as programs in India, Israel, Sweden, West Germany, Italy, Japan, Canada, and others. The National Intelligence Estimate (NIE) argued that India was the only new state likely to develop nuclear weapons, concluding that “there will not be a widespread proliferation …over the next decade. ”
May 20, 1965
Intelligence Note from Thomas L. Hughes to the Secretary, 'Swedish Military Chief Seeks Appropriation for Nuclear Weapons in Next Budget'
In a move interpreted by INR as part of a pro-nuclear “propaganda campaign,” Swedish Supreme Commander Torsten Rapp reportedly asked for funds for to cover the costs of nuclear weapons acquisition.
March 20, 1967
Research Memorandum REU-16 from George C. Denney, Jr., to the Secretary, 'Swedish Decision to Cut Military Spending Causes Defense Review, Reduces Likelihood of Nuclear Weapons Acquisition'
The Swedish government rejected Supreme Commander Torsten Rapp’s proposals to fund a nuclear weapons program. This INR report from March 1967 on proposed cuts in defense spending suggested that the possibility that Sweden would acquire nuclear weapons had grown even more remote.