Throughout his life Pau Casals fought constantly for peace, justice and freedom. From the very beginning he refused to play in countries that did not respect democratic principles and in the final years of his life he joined protests against numerous wars and the use of nuclear weapons.
In 1971, on the occasion of the premiere of the Hymn to the United Nations, which he had composed, UN Secretary-General U Thant awarded him the United Nations Peace Medal in recognition of his stance.