In May 1963 it looked as though negotiations for the Partial Nuclear Test Ban Treaty between the U.S. and the Soviet Union had failed. For the title of this cartoon, Herb Block quoted from Shakespeare's Macbeth to indicate the folly of President John F. Kennedy and Soviet Premier Nikita Khrushchev's failure to agree to limit nuclear testing. Block's famous character, Mr. Atom, snuffed out the light of Test Ban negotiations to represent the darkening mood of the United States during the Cold War. Protest against nuclear weapons persisted, compelling the Cold War leaders to come back to the table and sign the treaty, which they did in July 1963.