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.”
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. ”
April 14, 1967
Intelligence Note 292 from Secret Allan Evans to the Acting Secretary, 'Japanese Expert Considers Nuclear Defense'
INR assessed several recent newspaper articles by Kiichi Saeki, a defense expert close to the government, whose thinking was “noteworthy for [its] frank consideration of Japan’s need for nuclear-defense planning to cope with Communist China’s growing potential.”
September 26, 1972
Record of the Second Meeting between Prime Minister Tanaka and Premier Zhou Enlai
Zhou Enlai and Tanaka Kakuei discussed the Taiwan issue, especially for Japan-Taiwan relations after Japan-China diplomatic normalization. Zhou mentioned that he wants to start "establishing a new relationship between Japan and China."