A Cuban Defense Ministry communiqué details the “heroic defense” by Cuban and Angolan troops of Cuito Cuanavale against a South African onslaught. The brunt of the fighting was done by local Angolan forces, which successfully managed to repel the South African invaders.

Seeking “constructive engagement” with the apartheid regime, the Reagan administration wanted the South Africans to keep a lid on their nuclear weapons program. The NIE’s top-secret status was compatible with one of the elements of the 1984 estimate: that any revelations that broke the regime’s “calculated ambiguity” about its nuclear status would put Washington in an “awkward position” by “fir[ing] the drive” for the sanctions and disinvestment campaigns which the administration was trying to avoid. Analyzing the motives for the nuclear program, the CIA found it “irrelevant” to any threat that the regime was likely to face.A key issue was whether South Africa had a nuclear arsenal. On that problem, the NIE dovetailed with the view taken by NIE-4-82: South Africa “probably has the capability to produce nuclear weapons on short notice.” That was accurate, but U.S. intelligence may not have known that the regime’s leaders had already decided to build a stockpile of 7 weapons, with six weapons assembled during the 1980s.

Telegram from the Argentine Embassy in Brasilia reports on US Senator Alan Cranston’s claim that China was proliferating nuclear technology to countries like Argentina, Brazil, Iran, Pakistan, and South Africa. The telegram reports that both Brazil’s Foreign Ministry and China’s Embassy in Brasilia denied the charges. Part of the telegram is hand-highlighted , where a Brazilian diplomat says that the only deal between China and Brazil was the one signed by President Figueiredo during his visit to Beijing in 1984.

Alarmed that South Africa may be capable of developing nuclear weapons, the IAEA calls upon South Africa to submit its nuclear facitilies to agency safeguards, and calls upon all IAEA member states to hault nuclear cooperation with South Africa.

South African Minister of Foreign Affairs "Pik" Botha and President Reagan meet in Washington, DC. South African Ambassador Sole, the note taker, interprets Reagan's friendly opening comments as "the inference clearly being that he had no illusions about democratic rule in Africa." They discuss the situation in Namibia and Angola, and their shared opposition to Soviet and communist influence in the region. Botha also asks Reagan to help South Africa's souring relations with France regarding nuclear cooperation. Botha states that "South Africa was not preparing or intending to explode a nuclear device, but[...] could not afford publicly to surrender this option."

Record of the 211th Plenary Meeting of the 23rd International Atomic Energy Agency General Conference in New Delhi. The Conference discusses the credentials of the delegate from South Africa, with a number of countries proposing that the delegate should be rejected due to South Africa's continued policy of Apartheid.

South African Prime Minister Vorster denies the existence of a South African nuclear program and lists hostile steps taken by the United States to exclude South Africa from international nuclear and atomic energy groups. He concludes that "it would seem... the United States officially holds the view that stability in Southern Africa and the future of our country is to be sacrificed in the hope of stopping Soviet expansionism."

Mallaby reports on a conversation at the Nuclear Suppliers Meeting with the US Deputy Under-Secretary for Security Assistance, Nye, on whether the US would raise the issue of South Africa's Kalahari nuclear testing facility. The US assumption was that the South Africans intended to "be on the brink of having a nuclear weapons capability" in order to "moderate Western diplomatic pressure on her about racial and other issues."

Memorandum on UK position at Lagos Conference on Apartheid about Soviet allegations of South African nuclear weapons development.

US statement to the UN General Assembly delivered by delegate Father Hupp. The statement explains the why the US voted no on a series of resolutions regarding South Africa. These included resolutions on an arms embargo, sporting boycott and other resolutions concerning Apartheid. It also voted no on a resolution condemning Israel for arms sales to South Africa.