LONDON. — NELSON MANDELA has recently announced that he is not a socialist. This is enormous progress for a man of the radical left who, during his long incarceration, was cruelly deprived of exposure to the swirling currents of intellectual change in the world outside.
It is also remarkable when one considers that for most of his life his only substantial white allies, apart from a few churchmen and a handful of liberal intelligentsia, were members of the South African Communist Party. Even today communist members make up a significant part of the executive of Mr. Mandela's African National Congress. President F.W. de Klerk had to swallow hard when Mr. Mandela insisted that Joe Slovo, head of the ANC's military operations, as communist as he is white, accompany him to their negotiations.
In their hearts party members may still believe, as anachronistically they continue to wave the hammer and sickle at ANC rallies, what the first black member of the party reported after his visit to Moscow in 1924: ''The Africans are being kept in subjugation by British finance capital and its local ally, Afrikaner imperialism, in order to provide superprofits.'' But their hearts no longer mesh with their minds; in recent interviews Mr. Slovo himself appears to turn his back on much of the old rhetoric.
Yet, for all Mr. Mandela's new perceptions of the need for economic decision-making to be free from heavy-handed political diktat, he has not modified one whit his opposition to any amelioration of the sanctions imposed on South Africa by its principal trading partners.
The economy is in a serious recession. Sanctions have starved it of the kind of foreign investment that brings in the technology that a sophisticated industrial society like South Africa needs to to remain productive and competitive -- and, not least, to provide the jobs for the swelling urban black proletariat.
Nevertheless, Mr. Mandela devotes immense energy on his tours of North America, Europe and, this week, Australia to drive home the message that sanctions must be kept in place until the ANC decides that progress toward majority rule is ''irreversible.''
Mr. Mandela is making the bad mistake of trading the big needs of the long term for the marginal needs of the short. If he is not careful, when majority rule arrives, he will inherit an economy that foreign investors won't want to take a second look at: run-down and dilapidated and, moreover, besieged by massive unrest from a seething mass of discontented unemployed, inflamed with bitterness at the realization that black rule has produced nothing for them.
The pressure then to compound the problem will be irresistible -- divide up what cake there is -- give the black poor their long-deserved pay rises, social services, subsidized food and transport. This will be suicidal when there is a flight of confidence, a widening budget deficit, rising interest rates and a growing disillusionment among the mainly white business class.
Mr. Mandela needs to act now, while there's a fair chance of mounting a recovery. What stops him? He's won the essential political battle of freedom for himself and his associates, followed by honest negotiation with the government toward the mutually agreed goal of truly multi-racial government. The ANC has acknowledged the rapid rate of progress by formally suspending the ''armed struggle.''
Does Mr. Mandela fear that suddenly President de Klerk would put all this progress into reverse gear? Surely he knows that if this government tried to turn back it would collapse. Its raison d'etre in the eyes of a precarious majority of white voters is finding a way to majority rule and peace while protecting legitimate white interests.
Perhaps Mr. Mandela worries that the white electorate, alienated by growing internecine black violence and the fear of what is to come, will vote Mr. de Klerk out and install a rightist, racist government that will renege on all that has been achieved.
But this is exactly why Mr. Mandela needs to show that he can look past the next telegraph post. He badly needs to demonstrate that he'll buck rank-and-file black opinion -- and the views of hard-liners in his own executive -- and reach out to the future. This means working to end the growing black violence by burying the hatchet with his principal black rival, Chief Mangosuthu Buthelezi -- who is against sanctions -- and assuring him they'll settle their ranking among public opinion in the ballot box.
Above all it means restoring health and vigor to the economy, showing the middle ground of white opinion that he has the stuff to be a serious leader of a multi-racial society. Moreover, this serves his own long-term interest. If Mr. Mandela comes to power with an economy beginning to purr, then there will be the room for maneuver to start meeting frustrated black aspirations.
Mr. Mandela must call for the ending of sanctions now. Not to do so will ensure a deteriorating future for the black masses, more township violence and a greater backlash among the whites. Then it will be: ''Cry, The Beloved Country.'' No one will be able to stop South Africa tearing itself apart.