Thant announced in 1966 that he would not stand for a second term, but he accepted a draft when the Security Council assured him that he would not be a "glorified clerk." On December 2, 1966, the General Assembly re-appointed Thant to a term ending on December 31, 1971, on the unanimous recommendation of the Security Council. During his second term, he oversaw the entry into the UN of dozens of new Asian and African states, and was a firm opponent of apartheid in South Africa. He also established many of the UN's development and environmental agencies, funds and programmes, including the UN Development Programme (UNDP), the UN University, the United Nations Conference on Trade and Development, United Nations Institute for Training and Research (UNITAR), and the UN Environmental Programme. The Six-Day War between Arab countries and Israel, the Prague Spring and subsequent Soviet invasion of Czechoslovakia, and the Indo–Pakistani War of 1971 leading to the birth of Bangladesh all took place during his tenure as secretary-general.