jul 2, 1958 - 1958
July 2 - President Eisenhower signs amendments to the 1954 U.S. Atomic Energy Act which opened the way to a bilateral agreement between Britain and America on nuclear weapon design information.
November 1958 to September 1961 - U.S., U.K., and U.S.S.R. observe an informal moratorium on nuclear tests.
Added to timeline:
atomic and nuclear physics