Statements by Indonesian authorities notwithstanding, INR analysts did not “believe that Indonesia possesses the facilities, personnel and radioactive material necessary for producing an atomic device with any speed.”

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

Discussion of a British list of countries that were actual or potential manufacturers of inverters. The U.S. does not want to approach any "nuclear threshold states" yet because some might not cooperate or might inform Pakistan. Also discusses strategies for approaching the Soviet Union and China in the future.