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 document provides an overview of the London Nuclear Suppliers' Meeting which included the addition of the five newest countries to the original seven. Most old and new members were receptive when Washington lobbied them to support a “long term and stable regime of restraint” on the export of sensitive enrichment and reprocessing technology. While the French were supportive of the moratorium proposal, the Germans were uncomfortable with it, not least because of the implications for their deal with Brazil.

U.S. demarche and "non-paper" on Pakistan's attempts to complete the plutonium reprocessing plant and develop nuclear weapons. Sent to 12 countries to ensure that they "exercise vigilance and appropriate control to deter Pakistan from acquiring sensitive facilities."