In Israeli-South African Relations : On the Mend?, written in 2004, Kristin Nelson discussed some of the historical background to lingering tensions between the South Africa’s Australian National Congress (now in Government, once a hunted organization) and the Israeli regime.
Here’s an extract (emphasis added):
At the height of Apartheid Israel ignored international sanctions against South Africa, citing its own vulnerability to such tactics. It continued to sell roughly (US$) 600 million worth of arms per year to the white minority government before eventually banning further military contracts in 1987.

Nelson Mandela: when he was younger, Israel collaborated with his jailers
Before the early 1990s and the release of Mandela, mutual aid between the two governments evolved out of a natural fraternity: both were technologically advanced, militarily powerful nations that felt surrounded by hostile neighbours. During the 1970s this affiliation extended into the field of nuclear weaponry when Israeli experts helped South African to develop at least six nuclear warheads.
Although the extent of their covert collaboration is not entirely clear, Israel is known to have supplied technical assistance to South Africa in exchange for no less than 300 tons of uranium. Several Israeli nuclear scientists, including Ernst David Bergmann (the “Oppenheimer of Israel”), visited South Africa in 1967, and evidence of increasingly close relations accumulated throughout the 1970s.
Collaboration between South Africa and Israel over nuclear weapons was well-known 20 years ago – and strongly opposed by the world community as a whole.

Menachim Begin and Yitshak Shamir: an earlier generation of Israeli terrorist leaders, traded nuclear technology with Apartheid South Africa
Resolution A/RES/42/23 was passed by the 77th plenary meeting of the United Nations General Assembly on 20th November 1987. Part D, entitled Relations between Israel and South Africa, said:
The General Assembly,
Reaffirming its resolutions on relations between Israel and South Africa,
Having considered the special report of the Special Committee against Apartheid on recent developments concerning relations between Israel and South Africa,
Taking note of the declarations of the International Conference on the Alliance between South Africa and Israel and of the Second World Conference to Combat Racism and Racial Discrimination,
Alarmed at the increasing collaboration by Israel with the racist regime of South Africa, especially in the military and nuclear fields, in defiance of resolutions of the General Assembly and the Security Council,
Considering that such collaboration is a serious hindrance to international action for the eradication of apartheid, an encouragement to the racist regime of South Africa to persist in its criminal policy of apartheid and a hostile act against the oppressed people of South Africa and the entire African continent, and constitutes a threat to international peace and security,
- Again strongly condemns the continuing and increasing collaboration
by Israel with the racist regime of South Africa, especially in the military
and nuclear fields; - Demands that Israel desist from and terminate forthwith all forms of
collaboration with South Africa, particularly in the military and nuclear
fields, and abide scrupulously by the relevant resolutions of the General
Assembly and the Security Council; - Calls upon all Governments and organizations to exert their
influence to persuade Israel to desist from such collaboration and abide by
the resolutions of the General Assembly; - Requests the Special Committee against Apartheid to publicize, as
widely as possible, information on the relations between Israel and South
Africa and especially the Declaration of the International Conference on the
Alliance between South Africa and Israel; - Requests the Secretary-General to render, through the Department of
Public Information and the Centre against Apartheid of the Secretariat, all
possible assistance to the Special Committee in disseminating information
relating to the collaboration between Israel and South Africa; - Further requests the Special Committee to keep the matter under
constant review and to report to the General Assembly and the Security Council as appropriate.

Modechai Vanunu: the heroic Israeli nuclear whistleblower - still denied his freedom by Apartheid Israel
One of the greatest achievements of Israeli/Zionist PR over in recent decades has been persuading a majority of ‘left-wing’, ‘progressive’ westerners that Israel shares their values.
The historical record shows what a grotesque myth this has been.