A NUCLEAR-FREE southern Africa is at last a real possibility. Late last month South Africa retreated from a decade-long antagonism to international inspection of its atomic facilities. South Africa may or may not once have intended to divert the product of its efforts to fueling a bomb. But now that President P.W. Botha promises to sign the Nuclear Non-Proliferation Treaty and permit the International Atomic Energy Agency to examine its previously top secret uranium enrichment plant, diversion could prove exceedingly difficult.
The agency already monitors South Africa's two French-built power reactors near Cape Town and has long been permitted to audit activities at a small American-supplied research reactor near Pretoria. But until now, President Botha and his predecessors have steadfastly refused to open the enrichment plant to outsiders. Its operations have effectively been shrouded in secrecy.
Because of South Africa's refusal to open the plant and its failure to sign the Non-Proliferation Treaty, the United States, other atomic powers, and most of the countries of Africa have suspected South Africa of constructing, or at least being able to build, a bomb. That is the impression that South Africa itself has long wanted to convey.
In the 1970s, South African Cabinet ministers hinted that they wanted to join the exclusive club of bomb builders - the US, the Soviet Union, Britain, France, China, Israel, and possibly Pakistan and India. Unlike the 134 nations that have signed the Non-Proliferation Treaty since its drafting in 1970, South Africa since 1976 has rejected all overtures to legitimize its operations.
In the late 1970s, too, Soviet and US satellites discovered what could have been a testing facility in the Kalahari Desert. South Africa denied that it was such a site, but work on it soon ceased. Then, in 1979, a US satellite detected a light flash characteristic of low-yield nuclear explosions. Experts speculated that either the South Africans or the Israelis (who had long cooperated with South Africa in the nuclear field) had been testing a small bomb. But no other forms of surveillance provided conclusive evidence that a device had been detonated.
A special US scientific committee decided that since there had been no increased radiation levels, the satellite could have been hit by a tiny space fragment. Moreover, since late 1979 there has been no renewed suspicion of South African success in this critical area.
South Africa is a major producer of uranium, largely as a byproduct of gold. It processes it as well, but no longer markets or otherwise controls the output of Namibia's Rossing mine, one of the largest in the world.
As a white minority government threatened by an angry black majority, South Africa presumably wanted ostentatiously to reserve its right to develop nuclear weapons as a last defense against external attack or indigenous revolt.
But on whom would whites drop a bomb? If locally, they themselves would doubtless be harmed. On neighboring black states? Again, even a fortress white South Africa could not have escaped both physical and diplomatic fallout. The uselessness of a nuclear option for whites, however beleaguered, has always seemed obvious to outsiders. Now the government seems to have accepted that argument.
There are two other less compelling reasons why South Africa acted so boldly and responsibly last month. Many of the countries belonging to the agency had planned to vote to end South Africa's membership at their September meeting in Vienna. South Africa would not have wanted to lose its access to the agency's technical expertise. Second, signing the treaty would greatly please the West and imply that white South Africans were, in at least one respect, good international citizens.
A better reputation is one of the ways white South Africa will benefit from a public decision not to pursue the nuclear armaments option. Cynically, Pretoria acknowledges that its conventional forces are sufficiently powerful to cope with present and foreseeable levels of internal violence, and with any Africa-mounted attacks from across its borders. The futility of building a bomb with no realistic target on which it could be dropped is also acknowledged.
When Mr. Botha formally agrees to sign the treaty and does so, it will mark South Africa's international maturity. If it happens, it will also signify a new willingness to cooperate with the West.
Robert I. Rotberg is academic vice-president for arts, sciences, and technology at Tufts University.