Though the UN's primary mandate was peacekeeping, the division between the US and USSR often paralysed the organization, generally allowing it to intervene only in conflicts distant from the Cold War. (A notable exception was a Security Council resolution in 1950 authorizing a US-led coalition to repel the North Korean invasion of South Korea, passed in the absence of the USSR.) In 1947, the General Assembly approved a resolution to partition Palestine, approving the creation of the state of Israel. Two years later, Ralph Bunche, a UN official, negotiated an armistice to the resulting conflict. In 1956, the first UN peacekeeping force was established to end the Suez Crisis; owever, the UN was unable to intervene against the USSR's simultaneous invasion of Hungary following that country's revolution. In 1960, the UN deployed United Nations Operation in the Congo (UNOC), the largest military force of its early decades, to bring order to the breakaway State of Katanga, restoring it to the control of the Democratic Republic of the Congo by 1964. While travelling to meet rebel leader Moise Tshombe during the conflict, Dag Hammarskjöld, often named as one of the UN's most effective Secretaries-General, died in a plane crash; months later he was posthumously awarded the Nobel Peace Prize. In 1964, Hammarskjold's successor, U Thant, deployed the UN Peacekeeping Force in Cyprus, which would become one of the UN's longest-running peacekeeping missions. With the spread of decolonization in the 1960s, the organization's membership saw an influx of newly independent nations. In 1960 alone, 17 new states joined the UN, 16 of them from Africa. On 25 October 1971, with opposition from the United States, but with the support of many Third World nations, the mainland, communist People's Republic of China was given the Chinese seat on the Security Council in place