African nations debate merits of single-party system. Majority adopt it as way to stem dissent from rival tribal groups

A debate is developing throughout Africa between defenders of the single-party system, such as the one Zimbabwe has just adopted, and proponents of a multiparty democratic parliamentary system. Zimbabwe's decision to become a single-party state at the end of the year makes it the 35th African country to adopt this form of government.

Six other African nations have purely military regimes, although one of them, Nigeria, plans to reintroduce political parties by the early 1990s. Ten countries maintain multiparty democratic systems. Two of the 10 - Senegal and Sudan - reverted to multiparty systems after experimenting with single-party rule.

The phenomenon of the African single-party state results principally from problems that have arisen because colonial powers created states whose borders encompassed a multiplicity of tribes. As a result, these African countries have not yet evolved into viable nation-states, according to academic studies on the subject and both foreign and African analysts.

Only four sub-Saharan African countries (Lesotho, Somalia, Cape Verde, and the Comoros Islands) are composed of single national groups. The rest include within their borders as many as 126 tribes (as in Tanzania) and seldom less than three or four major communities.

The post-colonial experience of most of these countries has resulted in sharp rivalries, often violent, between tribal or regional-based parties. In varying degrees these rivalries threatened the security of the new nation-states at a critical time before their institutions, mostly inherited from the colonial past, had an opportunity to adapt to meet the needs of their newly independent societies.

The general response to the postindependence crises, which arose in most new states, was to try to curb these tribally and regionally centered struggles for power by abolishing political parties.

This approach was justified on the grounds that traditional African societies were ruled by consensus, requiring the minority to submit to the will of the majority once this had evolved through open discussion. This, has been coined ``participatory democracy.''

But critics of this system, including foreign and African leaders, officials, and academics, say consensus is not a traditional African way of government. They point out that it was not generally practiced. Where consensus rule was practiced, they say it was restricted to tribes.

They insist that in multitribal and multicultural societies, it is possible to maintain consensus only by stifling opposition, often through harsh measures, and striking at the fundamentals of democracy. Repressing tribal politics they argue only produces other divisions.

Zimbabwe's experience illustrates the dilemmas African nations have faced in choosing their post-independence governments. During the war of liberation against the Rhodesian regime, two movements existed with a patriotic front. One was the Zimbabwe African National Union (ZANU), led by Robert Mugabe, which drew most of its support from the Shona clans of the north. The other was the Zimbabwe African People's Union (ZAPU), led by Joshua Nkomo, whose support came mainly from the Ndebele and Kalanga tribes of the south.

The overwhelming defeat of ZAPU in the preindependence elections left its supporters deeply dissatisfied and anxious about the future of their region. Some took up arms to challenge the new government - a struggle which assumed the character of a match between Shonas and Matabeles.

The resultant violence by both sides produced great bitterness and seriously destabilized the country.

The role of the white minority added to these difficulties. Many whites sought to maintain the racially exclusive electoral roll which was guaranteed for 10 years under the agreement that formed the basis for Zimbabwe's independence in 1980.

The leaders of ZANU and ZAPU, as well as many whites, concluded the only hope of repairing the damage caused by violent politics and of putting an end to the grave state of internal insecurity was to merge their parties and create a single-party state.

Elsewhere in Africa, similar attempts to harmonize the interests of conflicting power groups and to restore security through a single-party system have produced serious problems. Single-party rule does not seem to have succeeded in dampening tribal, religious, or cultural differences.

And the many Africans who challenge the assumptions and claims of this system note that Senegal, which now has 17 political parties, is more stable than during the brief period when political parties were curbed and criticism could not be put to open debate.