After the Japanese surrendered under nuclear bombardment, Einstein was often in the public eye. In May 1946 he became chairman of the newly formed Emergency Committee of Atomic Scientists, joining their drive for international and civilian control of nuclear energy. He recorded fund-raising radio messages for the group, and wrote a widely read article on their work. Einstein's appeals for nuclear disarmament had an influence among both scientists and the general public. He also spoke out in opposition to German rearmament, defended conscientious objectors against military service, and criticized the Cold War policies of the United States. An early and firm supporter of the United Nations, he was convinced that the solution to international conflict was world law, world government, and a strong world police force. "I am opposed to the use of force under any circumstances, except when confronted by an enemy who pursues the destruction of life as an end in itself."

Although his activity was limited by advancing age and ill health, Einstein made clear his commitment to civil liberties. He attacked racial prejudice and supported the black civil rights movement. He called for a homeland in Palestine for the Jewish people, in which the rights of Arabs would also be respected. Meanwhile, he supported the creation of a Jewish university in the United States (the future Brandeis University). When the House Committee on Un-American Activities maligned teachers and other intellectuals, Einstein publicly advised the people under attack not to cooperate, but to follow the principle of civil disobedience. He was equally uncompromising when he refused any association with Germany. He even rejected honors from his native land -- he could not forgive the murder of Jews by Germans.

In 1952 Einstein was offered the position of President of Israel, a chiefly honorific post. Old and sick, but at peace in his Princeton home and office, he turned down the invitation. His interest in public affairs, however, continued. In 1955 he joined Bertrand Russell in urging scientists toward mediation between East and West and limitation of nuclear armament. Meanwhile he was writing a speech for the anniversary of Israel's independence. An incomplete draft of the speech was found at his bedside after he died.