Switching sides: young blacks leave ANC for arms of Pretoria. South African police keep an eye out for disenchanted dissenters

For safety's sake, the slight, soft-spoken black man calls himself simply ``John.'' In the past decade, he recounts, he has fled his native South Africa, trained as an African National Congress activist in Angola, East Germany, and the Soviet Union - and beaten a dissident to death in what he terms an ANC ``prison'' in Angola.

Now, he has switched sides. He works for the South African police.

Hundreds of other blacks have made the same journey - even crossed the same fences - in the intensifying battle over South Africa's future. It is a tangled struggle, fought with ideology as often as with guns or mines.

It is a struggle both sides say they're confident of winning.

On the ground, there can be little doubt the momentum has shifted in the government's favor since the declaration of a state of emergency last June. For 21 months, the authorities - more often, their alleged black supporters - had come under violent assault in black townships.

In the six months before the emergency, an academic here calculates, there were some 120 separate gunfire incidents or mine explosions presumed to be the work of ANC supporters or of its military wing, Umkhonto we Sizwe (``The Spear of the Nation''). The figure was up 30 percent on the previous six-months - and nearly three times the figure for all 1984.

``The future is within our grasp!'' blared an ANC pamphlet handed to this reporter in a black township shortly before the emergency.

Since then, thousands of activists have been jailed without charge. ``The people responsible for the unrest have been removed from the community,'' declares Col. Jak Buchner, a top South African police expert on the ANC. ``There is no instigation, no more playing with emotions.''

The government has also curbed local news media coverage of the ANC, barring reports deemed likely to improve the political image of an organization increasingly seeking support from whites inside South Africa, and from Western governments. President Pieter Botha has stressed the tie between the ANC and the similarly outlawed South African Communist Party. He has argued that an ANC takeover would bring not a nonracial democracy, but Communist autocracy.

Separate interviews with John and Col. Buchner in Pretoria - and ANC officials in Lusaka - reveal the rivals' starkly different strategies, and assumptions.

Buchner, who has compiled profiles on some 200 captured or ``turned'' ANC men in the past 10 years, says patterns have emerged. His aim, he says, is to ``see these men as people'' - to trace their roots, discover what forces drive them.

Many of the armed men that the ANC has been reinfiltrating into South Africaleft after the black-student uprising in Soweto in 1976, he says. Virtually all had poverty, Christianity, and a lack of deep-rooted political militancy in common.

``They might have been involved in a stone-throwing incident, or attended a demonstration. But they weren't members of any political group.'' As the Soweto unrest spilled into other areas, they typically ``heard the police were looking for them,'' and fled to neighboring states until things cooled down.

``I went to further my studies in Swaziland,'' says John, whose smattering of Russian, and geographic description of his places of exile, lend apparent credibility to the account of his oddysey. ``There were many refugees in our school, and a strong ANC [recruiting] influence.'' Under ANC auspices, he says, he went to Mozambique for lectures in ``political strategy;'' to Angola for weapons training; then to East Germany for ``more advanced studies in topography, military engineering - and political theory.''

Above all, he says, he was taught ``conspiracy ... secrecy.''

He says he felt torn between an urge to ``liberate'' his country and, as a devout Christian, doubts about Marxist ideology.

Returning to Angola, he spent five years as a guard at an ANC camp known, he says, as No. 4. ``It was a prison ... for suspected infiltrators, agents, misfits - for suspicious people.'' John says he watched some of them being shot by firing squad. He participated in beating others - at least once ``beating a person to death.''

Sent to Moscow for what he describes as 10 months' training in infiltration, political agitation, and organization of ``cells of four people'' inside South Africa, John slipped back onto his native soil with two ANC comrades last year.

He says he was by then disillusioned with the ANC - its ideology, its ``violence,'' its laws of ``conspiracy.'' Also, he makes clear, he felt homesick. He says he did not dare turn himself in, figuring ``this would mean death.'' But the point proved academic: The police were waiting for him.

In what has become a pattern in recent years, Buchner and others ``debriefed him for several months'' - then recruited him, fairly certain he was never hard-core ANC material. ``We know,'' says Buchner, ``what the situation was after 1976.''

Gradually, he says, South Africa has built up a store of knowedge on ANC activities. It comes from captured infiltrators - and, he says, from agents inside the ANC abroad. ``In the case of most people, we know beforehand when ANC men are about to return.''

Buchner says the ANC faces mounting difficulties in finding official haven for its cross-border infiltrators in neighboring black states. ``The ANC,'' he adds, ``has no infrastructure here. They have some 3,000 trained people outside - of whom roughly 30 are active at any one time in South Africa.''

Some academics posit a higher figure. John says he's not sure: ``The cells are organized without one's being aware of the others.''

Whatever the numbers, the ANC has so far failed to unleash a full-scale ``armed struggle.'' Hopes for an open-ended national strike and a rebellion by South Africa's 25,000 black policemen - aired in the pre-emergency pamphlet - have not borne fruit. The ANC did, by last year, seem near to one shorter-term goal - to make black townships ``ungovernable.'' But independent analysts say it is unclear how much of the unrest was the direct work of the ANC. Buchner feels certain the initial upheaval - over rent in black townships - ``was not orchestrated.'' The ANC, he says, ``grabbed on to it.''

In Lusaka, ANC's base, officials seem very aware of South African moves to ``turn'' their activists.

``Habashwe Abafe!'' proclaims an ANC pamphlet distributed in South Africa: ``Death to the Traitors!'' It pictures seven ex-ANC men who testified against former cohorts in South African courtrooms.

But, suggests an ANC official, a main focus of the group's evolving strategy is long-term political organization in South Africa. While confirming an overlap between the ANC and the Communist Party, he stresses the ANC is an umbrella organization - of dedicated men who aim to topple a ``racist'' system.

``Regardless of the short-term effects, the imposition of the state of emergency is not a sign of strength,'' he says. ``It is a sign of weakness, a sign that this is the only way the South African government feels it can rule.''

John does not underestimate the power of the ANC's political weaponry. ``People [in the townships] can't even tell you what the strategy and tactics of the ANC are. But still, they say the support the ANC. The ANC is bringing propaganda and agitation to the youth. This thing is spreading.''

According to Buchner, the ANC is now seeking to minimize the effect of South African penetration: by training black exiles more rapidly, reinfiltrating them in months.

He adds that he has begun to discern a new ``exfiltration'' of young blacks to neighboring states, similar to the flight after 1976.

``But,'' he adds, ``there is no `revolutionary climate' here. There are revolutionary-minded people who try to influence others ... the dissident types, especially in our cities.''

ANC sources counter that their supporters remain able to organize, in township ``street committees'' and other grass-roots bodies, despite the state of emergency.

This report was written in conformity with South Africa's press restrictions.