Pretoria not cowed by US sanctions. Sanctions expected to hurt, but not challenge S. Africa's military and economic power in region

South Africa's President, in a speech shortly before the United States voted on economic sanctions, strayed from his typewritten text. President Pieter W. Botha harked back to last Christmas, when, he said, many assumed that his government might fall under the weight of black political violence and foreign pressure.

``They said Pieter W. Botha will be out,'' the President told supporters at Pretoria City Hall. But, he added to a storm of applause, ``I'm still here. . . .''

The remark is a timely reminder of the South African government's political will, economic reserves, and military muscle.

US sanctions, the toughest yet imposed by a major Western power, will hurt South Africa. ``But it is an absolute delusion to believe the sanctions will bring this government to its knees,'' says one of President Botha's most prominent white-liberal foes, Helen Suzman.

Seconding her view, in a separate interview, was Hermann Giliomee, a top South African professor and political affairs writer. ``On none of the accepted prerequisites for revolution -- or governmental collapse -- does this government seem vulnerable.''

Specifically, notes Professor Giliomee, South Africa retains sufficient revenue sources to make foreign-debt payments, keep the economy afloat, and support its security force and civil-service structures. The security forces ``have the capability to handle any present challenge. Perhaps most importantly, ``the ruling group is totally united. There is no prospect of a split at the top.''

In regional terms, South Africa is a superpower. Its armed forces, which can field nearly half a million troops and reservists, have no African equal. They have helped insurgents in Angola at least offset Cuban Army support for the government. Troops have also been used in the crackdown on black violence here.

Adds one official privately, ``So far, we have brought only a small part of our overall power to bear.''

Economically, South Africa dwarfs black neighbor-states. Immediate neighbors -- Lesotho, Swaziland, and Botswana -- get electric power from South Africa. Virtually all their imports and exports go through South Africa. Pro-sanctions states like Zambia and Zimbabwe depend on South Africa to transship more than half of their imports.

South Africa, itself, is a key exporter of minerals that the world craves. Gold is but one. South Africa is a leading producer of ferrochromium, vanadium, and platinum, which are used in space-age alloys for everything from cars to Western weaponry.

The extent to which South Africa can, or will, use its power to retaliate against sanctions remains unclear. Some exporters seem likely to suffer badly from the US restrictions. These include fishermen and some clothing exporters.

But the country's largest employers, the mines, seem likely to suffer less. The US bill excludes gold, platinum, and other minerals from trade restrictions. Coal is included. But the main customers for South African coal are West Europe and Japan. They have not so far imposed a coal embargo.

Foreign Minister Roelof Botha, in a telephoned warning to US senators before last week's sanctions vote, vowed to halt transshipment of US grain to neighbor-states. Foreign Minister Botha said South Africa would also respond to sanctions by stopping purchases of US grain, having bought some 160,000 tons of this year's surplus.

However, there is no sign yet that South Africa will bar other grain suppliers, such as like Australia or Canada, from reaching black African markets. South Africa's own purchases of US grain have not been, in most years, crucial in world market terms. The exception was in late 1983 and 1984, when South African farmers were hit by drought.

``The minerals area is far more important to the US,'' says a market expert here. ``But one must remember South Africa's own economy could pay a heavy price by retaliating there.''

More likely, suggests Giliomee, is that South Africa will make good on hints at spreading the cost of sanctions to black African neighbors. Any new employment slump would probably be handled by favoring domestic laborers over the some 1 million migrants from neighbor-states.

Domestically, Giliomee predicts, the effect of any fallback in economic growth will be felt by black South Africans before whites. ``If driven into a corner, this government -- any government -- will first look after its own constituents.''

The government's strategy of gradual race-policy reform, though angrily dismissed as inadequate by many black leaders, costs money. Investment in areas like black education could suffer early in any budgetary squeeze.

Most pundits here predict that US sanctions will reinforce a government resolve to retrench: to put political reform at least temporarily on the back burner, while cracking down on black unrest and consolidating support among whites.

Those who do not share this view cite what is best called ``the Iranian scenario.'' This refers to the fall of the apparently unassailable Shah of Iran at the hands of a tidal wave of street opposition.

President Botha, in imposing a nationwide state of emergency in June, indirectly referred to the lessons of Iran.

Yet the cause of the Shah's fall, in the official view, was a failure of will at the top -- and a failure of political vision by the Shah's nominal allies, notably the United States. The US sanctions are seen by officials here as a new failure of vision.

Still, they seem newly determined to resist any failure of will. In recent speeches, President Botha has vowed to bring his country through the challenge of foreign sanctions -- ``and emerge stronger.''

``Nobody,'' Botha says, ``should ever expect us to confuse reform with surrender.''

This report was filed under South Africa's emergency regulations, which prohibit reporters from being ``within sight'' of any unrest, any ``restricted gathering,'' or any ``police actions''; from reporting on arrests made under the emergency regulations; and from relaying information deemed subversive.