[en] The evolution of international safeguards from the Acheson-Lilienthal Report of 1946 through implementation of the nuclear Non-proliferation Treaty in the 1970's with attention to the political considerations and evolving nuclear activities which influenced this development. Specific steps discussed include: the U.S. proposal for an International Atomic Energy Authority, presented by Bernard Baruch in 1946, President Eisenhower's Atoms for Peace proposal in 1953, discussions leading to the Statute of the International Atomic Energy Agency, adopted in 1957, and the formal definitions of IAEA safeguards in the documents INFCIRC/26, 66 and 153 in 1962, 1966, and 1970, respectively