If we look at the central zone in Africa south of the Zambezi river as a single region, we see that colonisation and settlement by Afrikaans-speakers and the British had brought the entire region under white rule by the beginning of the 20th century, but also that military conquest and settlement had established the amaZulu in the area of modern Zimbabwe, far to the north of King Shaka's territory in KwaZulu-Natal.

Under their kings Mzilikazi and Lobengula, these northern Zulu-speakers, the amaNdebele, established their own military and political supremacy over the resident Shona-speakers in the mid 19th century, until both peoples were conquered by the British under the hand of Cecil Rhodes, who had consolidated economic, political and military power through the De Beers company and as prime minister of the Cape Colony.

The Gukurahundi massacre of more than 20,000 isiNdebele-speakers in the 1980s by the government of Zimbabwe, under Robert Mugabe, makes it clear that power was simply transferred in 1980 from one sectional political authority to another in the new state: from white minority rule to sectional rule by a tribal chauvinist party, ZANU, representing the narrow interests of a despotic elite composed of Shona-speakers.

In this sense, nation-building failed in Zimbabwe, almost from the start. One sectional tyranny replaced another, maintaining itself by use and control of violence in the hands of the state, while this state became the instrument for looting of the wealth of the entire society by a parasitic and murderous elite.

As a Mafia-type kleptocracy displaying its modesty beneath a charade of fake elections and the dance routine of judicial process, this killer regime was already in place as a model for the country to its south, 14 years before the first democratic elections in South Africa in 1994. The issue was: would South African constitutionalism spread north to Zimbabwe, or would Zimbabwean dictatorship and kleptocracy spread south to South Africa?

Advocacy of the regime of Robert Mugabe this month by the African National Congress Youth League, headed by Julius Malema, in defiance of a South African government delegation to Zimbabwe including Mac Maharaj - one of the earliest and bravest heroes of the military struggle by the ANC and the South African Communist Party against apartheid - now moved this issue to a new, much sharper phase. The Mugabe model now claimed its own aggressive, organised and institutional representative within the ANC itself, making rubbish of the claim of the South African government under President Jacob Zuma to be the neutral umpire of a democratic settlement in Zimbabwe.

Even before the announcement of the existence of Umkhonto we Sizwe (MK) in December 1961, Maharaj had been the first member of the Congress Alliance to be sent to another country for training (in underground printing operations and for military training, in East Germany); was brutally tortured by the security police in Johannesburg in 1964, before serving 12 years alongside Nelson Mandela and Jacob Zuma on Robben Island; was then one of the last leaders of MK to be detained, assaulted and interrogated (in July 1990, in the course of the Operation Vula arrests); and was a minister in the first democratic government.

In a 19-page foreword to Maharaj's biography by Padraig O'Malley, Shades of Difference: Mac Maharaj and the Struggle for South Africa (Viking/Penguin, 2007), Mandela states: "I respect Mac, and I love him. I call him Ngquphephe, after a one-eyed hero in a Xhosa folk-tale. O'Malley does my Ngquphephe proud." (p.20) Maharaj had lost the use of one eye when he was tortured in 1964.

At the hands of the ANCYL, the heritage of Mugabe has now trashed the heritage of Maharaj.

This presents a very serious threat to the people of South Africa, since Malema's advocacy of the Zimbabwe regime and its methodology of rule by violence violates the spirit of the Constitution of 1994, as well as the founding ethic of the ANC from its inauguration as the Native National Congress in 1912. Whoever perpetrates a massacre of 20,000 Zulu-speakers north of the Limpopo river can never be regarded as an exemplar of black emancipation in South Africa, except at the risk of unleashing the dogs of xenophobic conflict.

As the ANC and the nation prepare to commemorate an anniversary infinitely more significant than the 2010 World Cup, what is at stake here is the nature of the route to nation-building in Africa, by contrast with the road to self-destruction. Malema and the ANCYL put in question the nature and historic significance of the ANC itself. This is now the prime issue in black politics in South Africa, over-riding every other. There is no way it will not divide brother from brother, cousin from cousin, until a resolution of this conflict is achieved, one way or the other.

There is either the route of Mugabe, with its motif of theft and ethnic slaughter, or the route of Maharaj, with its moral foundation of anti-tribalism and non-racism.

This principle remains enshrined in the hymn of Ntsikana from the early 19th century, composed in isiXhosa and still sung today, which looks to the unity of peoples. It is expressed in the words:

"He is the one who brings together herds which oppose each other.
He is the leader who has led us on.
He is the great blanket which we put on."

(translation by JB Peires in Peires, The House of Phalo: A History of the Xhosa People in the Days of their Independence, University of California Press, Berkeley, 1982. p.73)

This hymn by Ntsikana was composed and sung in South Africa years before the amaNdebele crossed the Limpopo, and long before the arrival of the first white people in Zimbabwe.

Harmony between people of different tribal groupings within the ANC over its history of almost a hundred years was not achieved without difficulty, and sometimes great difficulty. At times it was severely under threat; and there is danger that an unravelling of the ties that bind is under way once again.

A look at the history of the ANC over the past 50 years is helpful in explaining this.

Extreme suspicion is still present among ANC members - many of whom spent years in exile in the camps in African countries to the north - about the powerful role of isiXhosa-speakers in the leadership of the ANC in exile under president OR Tambo, himself a Xhosa-speaker. It is not hard to interpret the wholesale dismantling of the governing structure of the ANC at the party's national conference at Polokwane in December 2007, followed by that of the government of the whole country, in terms - partly at least - of a readjustment of the previously dominant role over many decades of isiXhosa-speakers within the ANC, as represented at Polokwane by President Thabo Mbeki, both from his time in exile and subsequently at the head of government.

To the best of my knowledge, the clearest witness to this great fact of South African political life are the authors Thula Bopela and Daluxolo Luthuli, two isiZulu-speaking members of the ANC and Umkhonto we Sizwe (MK) from the 'Mgwenya' (or old-timer, veterans) generation of the 1960s, when they were members of the Luthuli detachment in MK in exile. Both men fought in the Wankie campaign in 1967, and were captured by the Rhodesian military forces. Bopela was sentenced to death, commuted to life imprisonment, and returned to South Africa only after 1990, while Luthuli was handed over to the apartheid regime, serving a 10-year sentence on Robben Island before he was released in 1979.

Having received military training in the 1960s in the Soviet Union, Luthuli resigned from the ANC some time after his release, joined the Zulu-speaking Inkatha Freedom Party and became commander and commissar of the IFP hit squads after further training by the South African Defence Force in the Caprivi Strip in the north-east corner of Namibia. After many battles, and many killings, he was reconciled with the ANC again only in 1993 after he had approached his former comrade-in-arms, Bopela, with the intention to make a reconciliation. The crucial ANC leader through whom reconciliation was made - thus putting an end to the cycle of mutual slaughter of Zulu upon Zulu, and between Zulu and non-Zulu, thus permitting the general election of April 1994 to take place in peace - was Jacob Zuma.

Thula Bopela, who arranged this process - which concluded with a meeting between Luthuli and Nelson Mandela, and Luthuli's subsequent induction into the SANDF at the rank of lieutenant-colonel - described himself in an article on the Friends of Jacob Zuma website on 21 January last year as "Head: Security Management at Parliament, and member of the media and communications team in the ANC Johannesburg region."

He is an important communicator of current ANC policy.

His and Luthuli's first-hand historical account, Umkhonto we Sizwe: Fighting for a Divided People (Galago, Alberton, 2005) - essential reading for an understanding of modern South African history - contains many riches, but among them is a passage that provides a sharp insight into the subterranean tremors that shook the ANC in exile, but did not shatter it.

This crucial passage concerns the nature of the leadership provided in MK in exile by a Communist Party member, former trade unionist and isiXhosa-speaker from the Western Cape, Archie Sibeko, as commander at Kongwa camp in Tanzania in the mid-1960s. Sibeko, Bopela and Luthuli are all alive, and should be brought together for a full-scale academic discussion and examination of the important event at Kongwa which the two authors relate, with as many other survivors from that period as possible.

This is all the more necessary, since Sibeko, whose MK 'travelling name' was Zola Zembe, is the author with Joyce Leeson of an earlier autobiographical account, Freedom in our Lifetime (Indicator Press University of Natal/Mayibuye, 1996),

which does not give any adequate detail about the events as later related by Bopela and Luthuli. One touches here on a live wire of electrical charge in the relations between the 'herds which oppose each other' in civil life in South Africa, and it is crucial to proceed cautiously.

Sibeko (Zembe) writes merely that the "worst disciplinary problem was just before I left Kongwa. Frustration led to a group of comrades from Natal stealing trucks and heading south, to make their own way home. It was a hopeless proposition, of course, and they were intercepted within 80 kilometres and brought back." (p.85) There is then a very brief passage on discussions that followed among ANC leaders as to how the matter was to be treated, which concludes with Sibeko noting that he was then sent by the ANC leadership to represent the organisation at the May Day celebrations in Cuba. No clue is presented as to what the nature of the "frustration" was, which led the "group of comrades from Natal " to take such a radical step, in violation of military discipline; nor to the nature of any disciplinary action then taken against them, or indeed, possibly, against Sibeko himself.

Bopela and Luthuli present a more complete, and more complex, picture.

Following their military training in the USSR, the two authors write, they were returned to Tanzania. "Kongwa was a negative experience for most of those who camped there," they relate. "Ugly things happened because there were ugly people among us. But there were also positive people there and they did positive and inspiring things. ...

"The commander of the ANC camp was a chap called Archie Sibeko. He was known by his nom de guerre of Zola Zembe. In the Western Cape he had been a trade union secretary. One would assume that somebody with a trade union or communist party background would emphasise the class approach to the struggle and not a tribal one. Zola Zembe, unfortunately for everyone, was Xhosa first and ANC second. He caused division by frequently calling for meetings to be attended only by people from the Eastern Cape. What was discussed at such meetings remained a mystery to guys from the Transvaal, Natal and the Orange Free State.

"...The fundamental ideological position of the ANC was, and still is, unity of the tribes, whether Xhosa, Sotho, Shangaan, Venda, Tsonga or Zulu. Zembe had been swept into a nationalist working class movement, but in his own heart of hearts he remained a Xhosa and an anomaly. The ANC called on us all to rise to the challenge of becoming nationalists, yet many people - perhaps unconsciously - brought their tribal baggage along with them. ...Tribal tensions in the camp grew, fuelled by such actions." (pp.45-46)

There is a good deal more in this book about the situation at Kongwa (though nothing about the stolen trucks referred to by Sibeko). There is no space here, however, to give this the attention it deserves. One of the most eminent members of the ANC who was present at Kongwa at that time is Dr Zola Skweyiya, the former Minister of Social Development, now High Commissioner in London, whose MK name was Zola Bona. Bopela and Luthuli give credit to him and many others for not having attended the Xhosa-exclusive meetings at Kongwa, though isiXhosa-speakers themselves. "It was people like that who kept the spirit of the ANC alive," they write. (p.46)

Dr Skweyiya should be asked to give his memories of that period. Rumours still circulate in the ANC that there were even killings at Kongwa of soldier by soldier. It is believed a leading role in putting an end to the disruption and conflict there was played by Moses Kotane and JB Marks - both long-serving members of the SACP. A proper historical account is urgently needed. The point is that the issue of tribal chauvinism received sufficient attention from the leadership of the ANC and the SACP to prevent the fragmentation of the organisation into tribalist fractions.

As it is, Bopela and Luthuli provide further invaluable evidence of what separates the ANC as a matter of principle from ZAPU and ZANU in Zimbabwe. Describing their joint training in Zambia in 1966 with ZIPRA troops of the Zimbabwe African People's Union (ZAPU), led by Joshua Nkomo and James Chikerema, prior to their joint engagment with ZIPRA in the Wankie campaign, they write:

"The ZIPRA men puzzled the MK soldiers. They spent much of their time boasting about what they intended to do to ZANLA [army of ZANU] if they ever met up in the bush. They swore they would wipe them out. ...It seemed they considered ZANLA the real enemy and not the Rhodesians". There is a good deal more in this book about the intensity of this tribal conflict in Zimbabwe, with convincing evidence of deliberate efforts by ZAPU and ZIPRA to overthrow the elected government of Rober Mugabe in the early 1980s, prior to the Gukurahundi massacres carried out by ZANU/state forces organised in 5-Brigade and trained for the purpose by North Korean advisers. As the authors say, "This ZAPU-ZANU rivalry would cause us great distress later." (p.53)

They conclude: "While we believe it was correct for ZANU-PF to view ZAPU as a serious security threat, the 5-Brigade operations in Matabeleland ... can never be justified or excused. ...It was clear that 5-Brigade had been sent to Matabeleland to rape women, kill men and burn huts, rather than curb dissident activity. ...The situation deteriorated into a well-orchestrated ethnic cleansing, with the Shona avenging on the Ndebele who had colonised them under Mzilkazi. The struggle for power between Joshua Nkomo and Robert Mugabe degenerated into a bloodbath. For a people who had just emerged from a liberation struggle against white colonialism, it was shameful and degrading." (pp.216-217)

It is not appropriate at this point to give further information, whether about anti-Zulu chauvinism within the ANC in exile continuing as late as 1991 (see my article, written for the support organisation Justice for Southern Africa in London, "A Purge of Zulu-speakers in ANC Camps in Tanzania?", 22 August 1991, published in Searchlight South Africa No.8, January 1992, pp.29-32), or about violent anti-Mpondo slogans shouted in the organised attack by local ANC structures on the Abahlali baseMjondolo settlement at Kennedy Road in Durban on the night of 28 September last year.

The point is clear. If the ANC now fudges the "shameful and degrading" endorsement of the Mugabe government by Julius Malema, as Bopela and Luthuli rightly describe the behaviour of this vile regime, it will in fact endorse what Bopela and Luthuli also call a "well-orchestrated ethnic cleansing" and a "bloodbath", in violation of the "fundamental ideological position of the ANC [which] was, and still is, unity of the tribes".

Jacob Zuma played a crucial and honourable role in binding up the nation's wounds in the approach to the elections in April 1994, when, as Bopela and Luthuli write, "South Africa teetered on the brink of full-out civil war". (p.255) It remains to be seen now whether as President he will undo this act of healing, and inflame the ancient wounds, with fatal consequences for the country.

Click here to sign up to receive our free daily headline email newsletter