Cousins also wrote a collection of non-fiction books on the same subjects, such as the 1953 "Who Speaks for Man? ", which advocated a World Federation and nuclear disarmament. He also served as president of the World Federalist Association and chairman of the Committee for Sane Nuclear Policy, which in the 1950s warned that the world was bound for a nuclear holocaust if the threat of the nuclear arms race was not stopped. Cousins became an unofficial ambassador in the 1960s, and his facilitating communication between the Holy See, the Kremlin, and the White House helped lead to the Soviet-American test ban treaty, for which he was thanked by President John F. Kennedy and Pope John XXIII, the latter of whom awarded him his personal medallion. Cousins was also awarded the Eleanor Roosevelt Peace Award in 1963, the Family Man of the Year Award in 1968, the United Nations Peace Medal in 1971, the Niwano Peace Prize and the Albert Schweitzer Prize for Humanitarianism, both in 1990. He also served on the board of trustees for Science Service, now known as Society for Science & the Public, from 1972 to 1975.