flash" was the result of a joint South African–Israeli nuclear bomb test. David Albright stated in his article about the "double flash" event in the Bulletin of the Atomic Scientists that "If the 1979 flash was caused by a test, most experts agree it was probably an Israeli test". In 2010, it was revealed that, on 27 February 1980, President Jimmy Carter wrote in his diary, "We have a growing belief among our scientists that the Israelis did indeed conduct a nuclear test explosion in the ocean near the southern end of Africa." Leonard Weiss, of the Center for International Security and Cooperation at Stanford University writes: "The weight of the evidence that the Vela event was an Israeli nuclear test assisted by South Africa appears overwhelming." Reed has written that he believes the Vela incident was an Israeli neutron bomb test. The test would have gone undetected as the Israelis specifically chose a window of opportunity when, according to the published data, no active Vela satellites were observing the area. Although the decade-old Vela satellite that detected the blast was officially listed as "retired" by the U.S. government, it was still able to receive data. Additionally, the Israelis chose to set off the test during a typhoon. By 1984, according to Mordechai Vanunu, Israel was mass-producing neutron bombs. South Africa The Republic of South Africa too had a clandestine nuclear weapons program at the time, and it falls within that geographic location. Nevertheless, the country had acceded to the Partial Test Ban Treaty in 1963 Later, concurrent with the end of apartheid, South Africa disclosed most but not all of the information on its nuclear weapons programme. According to international inspections and the ensuing International Atomic Energy Agency (IAEA) report, South Africa could not have constructed such a nuclear bomb until November 1979, two months after the "double flash" incident. Furthermore, the IAEA reported that all possible South African nuclear bombs had been accounted for. A Central Intelligence Agency (CIA) report dated 21 January 1980, that was produced for the United States Arms Control and Disarmament Agency, concluded that: The United Nations Security Council Resolution 418 of 4 November 1977 introduced a mandatory arms embargo against South Africa, which also required all states to refrain from "any co-operation with South Africa in the manufacture and development of nuclear weapons". Sasha Polakow-Suransky writes that, in 1979, South Africa was not