TRoubled Zaire finds fewer active backers in the West

Consider Zaire, a country the size of the United States east of the Mississippi. It has 26 million people. Three-quarters of them subsist on an annual income of less than $100. Two-thirds of them are illiterate. Its President, Mobutu Sese Seko, who has ruled the country for 16 years, is a millionaire many times over.

Yet Zaire is loved by the West.

The reason: raw materials. Zaire is rich in them. It has, for example, the world's largest known reserves of cobalt (about 30 percent of the world's total) , as well as huge quantities of other resources essential to industry and defense, including zinc, manganese, and copper. Zaire is also the world's largest producer of industrial diamonds.

Next month when French President Francois Mitterrand visits the US for the first time since unseating Valery Giscard d'Estaing in last spring's election, Zaire will be discussed.

President Reagan will want to know what action France will take if and when a force from without or within tries to conquer Zaire. Three years ago, that happened.

On that occasion, the West joined hands to counter the attack. French transport planes -- backed by military aid from Belgium and $13 million in "nonlethal" equipment supplied by the US -- flew 1,500 well-trained Moroccan troops into Zaire in a matter of hours to repel the invasion by Marxist guerrillas based in neighboring Angola. Without Western help, Mobutu might have become an ex-president and Zaire a prize for the socialist bloc.

At next month's Franco-American summit, President Mitterrand will tell President Reagan that this time, France's response may not be the same.

Under Mitterrand, France favors, at least in theory, staying cool and allowing African and other third-world countries to work out their own answers to their many problems. Not so the Reagan administration, which appears eager to lend a helping hand any time anywhere, especially if the problems take the form of foreign intervention.

France sees the third world in a different light. Last month, for instance, Jean-Pierre Cot, the minister for African affairs, ended a swing throug Africa arguing that the continent's vulnerability is rooted in economic backwardness and not in the threat of political destabilization. The answer: send more development aid.

For his part, President Reagan, too, appears ready to boost aid significantly , certainly in the case of Zaire, where it stands now at a nominal $31 million annually. But as other countries in black Africa begin to shy away from the new American administration, accusing it of leaning too far to white-ruled South Africa, President Reagan has recognized the importance of keeping Mobutu, a longtime ally surrounded by hostile governments, in power. Recently, he sent a 10-man team of military advisers to Zaire to report back on what he already knows to be the sorry state of the national Air Force. He also knows that Zaire's 60,000-man Army, while still trained by French and Belgian advisers, is cinsidered by most Western experts to be unfit to defend the country against serious attack.

Meanwhile, Mobutus's enemies multiply. Countless exiles opposed to his rule -- most of them living in Belgium, heading anti-Mobutu organizations that seem to spring up daily and claim strong support back home -- abound.

The latest is former prime minister Nguza Karl-I-Bond, who fled Zaire last month while still holding his post and demanded and received political exile in Belgium.

Last month, Mr. Nguza told several Belgian newspapers that he plans to overthrow Mobutu, and that his following in the Army is large.

No one, meanwhile, underestimates Mobutu's ability to keep his job. He has survived attempted coups, invasions from foreign territory, and resignations of senior aides and Cabinet members.

The economy, although on the upturn this year, has been in ruins for most of Mobutu's reign, which began in 1965 after 85 years of colonial rule by Belgium and five years of bloody civil strife in the early 1960s.

The secret of Mobutu's success in staying where he is has been his ability, through traditional dictatorial methods, to weld together the country's 250 tribal groups speaking 700 languages and dialects into something approaching national unity. Mobutu is also remembered warmly even today for having brought peace to a ravaged country in the post-colonial period.

Political and military analysts see no short-term threat to Mobutu's rule either from a bordering power (Angola, for example, has its hands full with South Africa) or from inside the country. But the seeds of instability remain -- extreme poverty, 17,000 Cuban troops in Angola, one million exiles overseas, longstanding border disputes with Zambia, pro-Soviet leanings in the Congo (Brazzaville).

Some observers say that the US may have to go it alone in providing military assistance to defend Mobuto against future attacks, even though France will increase other kinds of aid.

"I don't see the new French Socialist government sending military aid into Zaire as the previous government did three years ago," a Belgian government official says."And Belgium would probably follow the French lead again, as it did then, even though we still have major interests in the country and some 20, 000 citizens living and working there. The mood in France today is to settle crises through political channels, not with military force. Whether that will succeed or not, only time will tell."