Sept. 5, 1961 - President Kennedy ordered today the resumption of nuclear weapons tests by the United States. He specified that the tests should take place "in the laboratory and underground, with no fallout." The decision was taken after the Atomic Energy Commission announced that the Soviet Union had exploded a third nuclear device in five days. The President said in a statement that the U.S. had "no other choice." The President's statement signaled the end of a voluntary undertaking by the U.S. not to test nuclear weapons which was announced on Aug. 22, 1958, and went into effect Nov. 1, 1958.