"Tonight," bellowed the burly Afrikaner leader on the shattered stage, "was Blood River in Pietersburg. Tonight, the volk won a great victory in the fight to get back our fatherland."

The reference to the white Afrikaner pioneers' most celebrated victory over South Africa's indigenous blacks in 1838 hit an emotional button that sent the crowd in the packed hall into another wild round of stomping and cheering.

A forest of banners bearing a crooked cross resembling a swastika set in a white circle on a red background waved excitedly. Hands shot up in stiff-arm salutes. Eyes shone with the fever of mob hysteria. "Ah-Vee-Bee, Ah-Vee-Bee!" chanted the crowd, giving a pulsating rhythm to AWB, the initials, in Afrikaans, of South Africa's newest political organization, the far-right Afrikaner Weerstandsbeweging, or Afrikaner Resistance Movement.

Eugene Terre'Blanche, leader of the AWB, was in full cry and the crowd was caught in his spell, seemingly carried along on an emotional wave by the words that flowed in a rich, guttural torrent from his lips.

Here was a speaker in the mold of the 1930s demagogues, the first of his kind to turn up in South Africa's racially neurotic society where the political rhetoric is usually stilted and dry.

But as the banners waved and the orator thundered, the imagery was not so much of the Nazi Party at its height as in its early days, with brown-shirted "storm falcons" leading the rowdy mob into a political brawl.

The Nazi-lookalike AWB, which broke up a rally of South Africa's ruling National Party on Thursday, is not yet a proper political party. It is still a marauder organization, scouting ahead of the established parties of the far right.

But it is growing fast. Government sources guess that its membership has tripled since the beginning of this year. Estimates of its current size range from 50,000 to 100,000. Terre'Blanche, 46, a barrel-chested former policeman and rugby player who was once bodyguard to the previous prime minister, John Vorster, is its chief drawing card and driving force.

The AWB is still far from being able to pose an electoral threat to the government and it is doubtful whether it ever will. The demography of South Africa is such that even if half the Afrikaners defect to the far right, that will still be less than one-third of the overall white electorate.

But the AWB represents the aggressive emergence of the Afrikaners' deep-rooted survival instinct in response to the threat of black revolution now sweeping the country.

It is white violence responding to black violence, the white counterrevolution taking shape even before the black revolution has properly begun. It confronts the government with the formidable prospect of having to deal with violence simultaneously on two fronts, black and white.

For President Pieter W. Botha and his colleagues, the raw atavism of the AWB also arouses deep political fears. They see their own robust methods of 40 years ago, which fired up Afrikaner nationalism and brought them to power, now being turned against them.

That is the stuff of which political nightmares are made, and many observers here expect to see the government respond, perhaps disproportionately, to the threat it sees burgeoning on its right.

Some already suspect that Pretoria's military raids last Monday into three neighboring black states may have been primarily intended as a political gesture in the face of this threat.

The same goes for a rebuff to a Commonwealth team of "eminent persons," which was in South Africa at the most delicate stage of its peace-seeking mission when the raids were launched and when President Botha made a pointedly timed speech denouncing "unsolicited interference" by "meddling groups inside the country."

The Commonwealth group's aim was to open the White Militants Join S. African Fray Afrikaner Right Wing Seen Forcing A Harder Line by Pretoria By Allister Sparks Special to The Washington Post News Analysis

JOHANNESBURG, May 24 -- "Tonight," bellowed

"Tonight," bellowed the burly Afrikaner leader on the shattered stage, "was Blood River in Pietersburg. Tonight, the volk won a great victory in the fight to get back our fatherland."

The reference to the white Afrikaner pioneers' most celebrated victory over South Africa's indigenous blacks in 1838 hit an emotional button that sent the crowd in the packed hall into another wild round of stomping and cheering.

A forest of banners bearing a crooked cross resembling a swastika set in a white circle on a red background waved excitedly. Hands shot up in stiff-arm salutes. Eyes shone with the fever of mob hysteria. "Ah-Vee-Bee, Ah-Vee-Bee!" chanted the crowd, giving a pulsating rhythm to AWB, the initials, in Afrikaans, of South Africa's newest political organization, the far-right Afrikaner Weerstandsbeweging, or Afrikaner Resistance Movement.

Eugene Terre'Blanche, leader of the AWB, was in full cry and the crowd was caught in his spell, seemingly carried along on an emotional wave by the words that flowed in a rich, guttural torrent from his lips.

Here was a speaker in the mold of the 1930s demagogues, the first of his kind to turn up in South Africa's racially neurotic society where the political rhetoric is usually stilted and dry.

But as the banners waved and the orator thundered, the imagery was not so much of the Nazi Party at its height as in its early days, with brown-shirted "storm falcons" leading the rowdy mob into a political brawl.

The Nazi-lookalike AWB, which broke up a rally of South Africa's ruling National Party on Thursday, is not yet a proper political party. It is still a marauder organization, scouting ahead of the established parties of the far right.

But it is growing fast. Government sources guess that its membership has tripled since the beginning of this year. Estimates of its current size range from 50,000 to 100,000. Terre'Blanche, 46, a barrel-chested former policeman and rugby player who was once bodyguard to the previous prime minister, John Vorster, is its chief drawing card and driving force.

The AWB is still far from being able to pose an electoral threat to the government and it is doubtful whether it ever will. The demography of South Africa is such that even if half the Afrikaners defect to the far right, that will still be less than one-third of the overall white electorate.

But the AWB represents the aggressive emergence of the Afrikaners' deep-rooted survival instinct in response to the threat of black revolution now sweeping the country.

It is white violence responding to black violence, the white counterrevolution taking shape even before the black revolution has properly begun. It confronts the government with the formidable prospect of having to deal with violence simultaneously on two fronts, black and white.

For President Pieter W. Botha and his colleagues, the raw atavism of the AWB also arouses deep political fears. They see their own robust methods of 40 years ago, which fired up Afrikaner nationalism and brought them to power, now being turned against them.

That is the stuff of which political nightmares are made, and many observers here expect to see the government respond, perhaps disproportionately, to the threat it sees burgeoning on its right.

Some already suspect that Pretoria's military raids last Monday into three neighboring black states may have been primarily intended as a political gesture in the face of this threat.

The same goes for a rebuff to a Commonwealth team of "eminent persons," which was in South Africa at the most delicate stage of its peace-seeking mission when the raids were launched and when President Botha made a pointedly timed speech denouncing "unsolicited interference" by "meddling groups inside the country."

The Commonwealth group's aim was to open the way for the first direct negotiations between Pretoria and the outlawed African National Congress, the main black underground movement.

Sources close to the government indicate that, with reports showing that defections to the AWB were reaching hemorrhage levels, the Cabinet decided at a meeting May 6 that this was no time to release the imprisoned ANC leader, Nelson Mandela, and to legalize the black nationalist organization, as the Commonwealth team envisaged.

Nor was it felt that this was a good time to be seen negotiating with foreigners about such politically charged domestic issues, the sources report.

Instead, the raids into neighboring states followed six days later. The widely held belief here is that they were intended as a display of toughness to reassure party waverers that the government had not gone soft and was determined to crack down on black troublemakers.

Looking to the future, informed observers here believe the growth of the AWB is likely to continue exerting that kind of influence on the government.

They predict that the slow pace of reform to the apartheid system of segregation is likely to become slower still and remain strictly within the constitutional framework of legally defined race groups, in a way that will ensure the continuation of overall white minority control.

Outside critics will be told to be patient, the theory goes, and to take note of the right-wing threat that must be taken into account. As one western diplomat put it: "Every time we urge Pretoria to move faster we'll be asked, 'Do you want to see them come to power?' "

The Afrikaner Resistance Movement has been in existence for 13 years and, until recently, shown little sign of growth. Andries P. Treurnicht's Conservative Party, which broke from the government in 1983, was considered the movement to watch. It was trying to project an image of respectability to the increasingly middle-class Afrikaner voters. With President Botha's cautious reformism raising doubts in their minds, the party had benefited from a 20 percent swing to the right in five by-elections since last October.

The AWB was seen as no threat at all. National Party organizers felt its Nazi-like flags and salutes would surely frighten off modern, decent Afrikaners. Its policy of trying to reestablish the old Boer, or Afrikaner, republics of the last century as separate, pure-white states seemed so unrealistic that it was felt no intelligent voters could possibly take it seriously.

If anything, the Botha government regarded the AWB as mildly useful. It could use it to make conservative Afrikaners shrink from the right wing, and as a bogeyman to hold before foreign governments and English-speaking South Africans to justify not moving faster with the reform program.

Suddenly, that has changed.

In Pietersburg, the equivalent in racial terms of the American Deep South of an earlier era, the National Party rally this week was to be addressed by Foreign Minister R.F. (Pik) Botha, the foremost verligte, or reformer, in the Cabinet.

Terre'Blanche, sensing this to be his moment to strike and put himself on the map domestically and internationally, vowed that Botha "won't speak in Pietersburg."

Botha, a man with a reputation for pugnacity, vowed that he would. The scene was set for a trial of strength that evoked something of the atmosphere of a rugby cup final, the national sport beloved by Afrikaners. Supporters of both sides packed picnic baskets into their automobiles and set out for Pietersburg from all parts of the Transvaal.

Many were burly farmers in pick-up trucks. Some had revolvers thrust into their belts. In towns along the way, AWB supporters stood at the roadside waving their vivid swastika flags.

Two hours before Botha was due to address the rally, more than 1,000 AWB supporters were gathered in a singing, chanting mob outside the hall. Some of the women were dressed in the costumes of the Voortrekker pioneers, with ankle-length dresses and sun way for the first direct negotiations between Pretoria and the outlawed African National Congress, the main black underground movement.

Sources close to the government indicate that, with reports showing that defections to the AWB were reaching hemorrhage levels, the Cabinet decided at a meeting May 6 that this was no time to release the imprisoned ANC leader, Nelson Mandela, and to legalize the black nationalist organization, as the Commonwealth team envisaged.

Nor was it felt that this was a good time to be seen negotiating with foreigners about such politically charged domestic issues, the sources report.

Instead, the raids into neighboring states followed six days later. The widely held belief here is that they were intended as a display of toughness to reassure party waverers that the government had not gone soft and was determined to crack down on black troublemakers.

Looking to the future, informed observers here believe the growth of the AWB is likely to continue exerting that kind of influence on the government.

They predict that the slow pace of reform to the apartheid system of segregation is likely to become slower still and remain strictly within the constitutional framework of legally defined race groups, in a way that will ensure the continuation of overall white minority control.

Outside critics will be told to be patient, the theory goes, and to take note of the right-wing threat that must be taken into account. As one western diplomat put it: "Every time we urge Pretoria to move faster we'll be asked, 'Do you want to see them come to power?' "

The Afrikaner Resistance Movement has been in existence for 13 years and, until recently, shown little sign of growth. Andries P. Treurnicht's Conservative Party, which broke from the government in 1983, was considered the movement to watch. It was trying to project an image of respectability to the increasingly middle-class Afrikaner voters. With President Botha's cautious reformism raising doubts in their minds, the party had benefited from a 20 percent swing to the right in five by-elections since last October.

The AWB was seen as no threat at all. National Party organizers felt its Nazi-like flags and salutes would surely frighten off modern, decent Afrikaners. Its policy of trying to reestablish the old Boer, or Afrikaner, republics of the last century as separate, pure-white states seemed so unrealistic that it was felt no intelligent voters could possibly take it seriously.

If anything, the Botha government regarded the AWB as mildly useful. It could use it to make conservative Afrikaners shrink from the right wing, and as a bogeyman to hold before foreign governments and English-speaking South Africans to justify not moving faster with the reform program.

Suddenly, that has changed.

In Pietersburg, the equivalent in racial terms of the American Deep South of an earlier era, the National Party rally this week was to be addressed by Foreign Minister R.F. (Pik) Botha, the foremost verligte, or reformer, in the Cabinet.

Terre'Blanche, sensing this to be his moment to strike and put himself on the map domestically and internationally, vowed that Botha "won't speak in Pietersburg."

Botha, a man with a reputation for pugnacity, vowed that he would. The scene was set for a trial of strength that evoked something of the atmosphere of a rugby cup final, the national sport beloved by Afrikaners. Supporters of both sides packed picnic baskets into their automobiles and set out for Pietersburg from all parts of the Transvaal.

Many were burly farmers in pick-up trucks. Some had revolvers thrust into their belts. In towns along the way, AWB supporters stood at the roadside waving their vivid swastika flags.

Two hours before Botha was due to address the rally, more than 1,000 AWB supporters were gathered in a singing, chanting mob outside the hall. Some of the women were dressed in the costumes of the Voortrekker pioneers, with ankle-length dresses and sun hoods called "kappies." They carried flags of the old Transvaal and Free State republics, defeated by Britain in the Boer War of 1899-1901.

There were men in Stetson hats and high boots. Some carried riding whips. Young "storm falcons" in brown uniforms with shoulder flashes strutted about giving orders.

Banners were unfurled. Many were directed at Pik Botha, making fun of his nickname, which can be linked to the Afrikaans word for black to make it "pitch black." Others drew on the AWB's self-proclaimed Christian devoutness. One carried a quotation from the Book of Daniel about the division of the kingdom into parts of iron and parts of clay. The message was clear: iron and clay -- black and white -- don't mix, so keep them apart.

To secure the hall for themselves, National Party marshals had locked the doors and installed about 30 hefty men inside to guard the stage. Their mistake was that the bulk of their members, lacking the fervor of the AWB, were not there early enough to ensure that they would be first into the hall. They arrived after dinner, men in suits accompanied by women with coiffured hair, and they were shocked to see the AWB crowd there ahead of them.

The National Party has grown staid and respectable during its 38 years in power. Its members look more and more like those of wartime Prime Minister Jan Smuts' United Party, which the Nationalists ousted in 1948, and they were no match for those waiting to beat them into the hall.

As the crowd swelled, some AWB members broke open a side door and, with a key apparently provided by a sympathetic official, unlocked the main doors from inside. The mob swept in and charged the platform.

Two hours later, a police officer forced his way on stage and, using a bullhorn, told the crowd they were occupying the hall illegally and ordered them to leave. As the crowd jeered at him, the officer gave the order for his men to fire tear gas into the hall.

As the choking gas filled the hall, the big crowd stampeded for the doors. Many were trampled on. Several men, desperate for air, dived through sheet-glass windows.

They quickly reassembled outside, but again the police pumped tear gas into the crowd, sending them scattering away gasping abuse at the police.

It was a scene that has been repeated hundreds of times in the black townships of South Africa over the past year, but here, unbelievably, were Afrikaner police firing at Afrikaner people.

"Forgive them, for they know not what they do," declared Terre'Blanche in a final biblical flourish before driving away. But there was a sense that there will be no forgiving or forgetting what happened. As in the black townships, the violence in Pietersburg on Thursday night seemed to increase the bitterness and militancy of the far right.

It will grow, and some commentators here are suggesting that it may not be long before Terre'Blanche and some of his lieutenants openly propagate violent resistance to government reforms.