In 1968, Blum worked for the
United Nations Office of Legal Counsel. He was a member of Israeli delegation to 3rd
UN Conference on the Law of the Sea in 1973. In 1976 he was part of the Israeli delegation to the 31st session of
UN General Assembly. He served as Ambassador and
Permanent Representative of Israel to the United Nations for six years, from 1978 to 1984. He was a member of the Israeli negotiating team that drafted the peace treaty with Egypt (
Camp David Accords) in 1978, the
Blair House negotiations in March 1979 and the Israeli legal team at the Taba arbitration talks between Israel and Egypt between 1986 and 1988. As the Ambassador to the United Nations, Blum was often critical of it, saying that the UN "fans the flames of the Middle East conflict."
The New York Times quoted him as saying that "The essence of the
Middle East conflict has always been and remains the persistent enmity of
Arab states towards the Jewish national renaissance." As UN envoy, he made headlines for "scolding" a group of 133 American Jewish law students protesting
Israel's invasion of Lebanon and protesting
Jewish settlements in
West Bank and
Gaza. He questioned the factual, as well as the moral position, of the students' view, saying that they "have not given the slightest indication of their willingness to bear any personal consequences of their patronizing and fortuitous advice." ==Published works==