Zimbabwe took a decisive step backward last weekend when its leaders agreed to abandon their Western-style, market-oriented, multiparty form of government and economy. A congress of the ruling Zimbabwe African National Union (ZANU) decided to turn the country into a single-party socialist state, albeit gradually. Yet even the decision to convert slowly will frighten investors, Western allies and other donors, and even many Zimbabweans themselves.
The 6,000 delegates to the party's first assembly since its founding in 1964 ignored many of the practical risks. They agreed to make the transition to official socialism based on Marxist-Leninist principles ''in the fullness of time.'' As Prime Minister Robert Mugabe has long promised, the delegates favored discarding Zimbabwe's present form of government only in accord with the provisions of their country's British-given Constitution. That document, which was drafted in 1979 at the end of a civil war between local white colonial and African guerrillas, specified that no major shifts in the country's method of rule could take place before 1987 without unanimous parliamentary approval, and preferably not before 1990.
The Constitution guarantees that 20 whites shall hold seats in Parliament until 1990. Another 20 seats are now filled by members of the Zimbabwe African People's Union, which opposes Mr. Mugabe and one-party domination. His party holds 57 seats and another party, 3.
The fact that Marxist-Leninist methods and a single-party model were not demanded immediately indicates how successfully Mugabe has consolidated power in his own hands while deftly appeasing party radicals who demand these fundamental changes at once. Significantly, the congress also gave Mr. Mugabe the right to become an executive president, and permitted him almost alone to choose the members of a 13-member politburo that is destined to supersede the authority of Parliament.
Mr. Mugabe, a quiet-spoken Roman Catholic with ascetic attributes, who shuns smoking and drinking and lives modestly, received personal authority to impose a very stringent anticorruption code on all state officials. In tacit recognition of the failings of many of his colleagues, he will now have the power to purge those who misbehave as well as those who use their positions to amass ill-gotten wealth. Whether or not he will be able to wield this kind of broom, however, is questionable. In Tanzania and Zambia, where similar leadership codes were adopted years ago, very little has changed.
In the economic sphere, where Mugabe inherited a well-functioning modern capitalistic system run by whites, more than 150,000 of whom still inhabit the country, rapid change need not be expected, either. Much as he has talked about socialism, Mugabe has always behaved with striking pragmatism. He and his finance minister have followed an orthodox fiscal and economic program, and now adhere closely to the prescriptions of the International Monetary Fund. Unlike other African socialists, Mr. Mugabe has raised producer prices to realistic levels and refused to subsidize consumers. In so doing, even in a time of drought, he has tried to keep Africans on their farms and out of the cities. He has welcomed American and other investors to the industrial sector, too. There are no signs that Mugabe wishes to alter Zimbabwe's present recipe for prosperity.
Other than Nigeria and the Ivory Coast, Zimbabwe has the most powerful, sizable economy in black Africa. With a population of 8 million, and traditional export earnings from corn, tobacco, and a variety of other agricultural commodities, as well as gold, copper, and other minerals, Zimbabwe has been among the very few African countries able to feed itself. An unusual two-year drought now imperils its development, but if this year's rains are ample, Zimbabwe should revive.
Zimbabwe will not change soon, and it never alters anything fundamental except the number of its permitted parties. Already ZANU is dominant in everything. But confidence in the country's future, in the US, Europe, and South Africa, will suffer severely as a result of the language and headlines generated by the party congress. Zimbabwe, which promised not to make the mistakes of its predecessors, has now fallen into the same trap.