Before the communist takeover of South Vietnam in 1975, Thuyet worked for a foreign company and her brother was a junior Army officer assigned to a government security branch. Now, eight years later, she waits for her brother's release from a reeducation camp, and for permission to leave the country.

It is a wait that grows increasingly desperate, with no end in sight. Conditions in the reeducation camp are poor and her brother's health is declining, Thuyet says, and she has no relatives abroad to help her qualify for legal departure.

"My brother was told he would be in for one month," she says. "But it has now been eight years. Then they said they would let him out soon. But with this regime, 'soon' can mean 20 years."

Nguyen Van Suu, 33, was a Navy lieutenant who trained in the United States and served in Danang before the communist victory. After spending a year in reeducation, he says, he tried to flee the country by boat, was caught and served 4 1/2 years in jail. After his release, he says, he tried again nine more times, finally succeeding last August.

Now, for all practical purposes, he is a prisoner again as he waits in a dreary former leprosarium on Hong Kong's Hei Ling Chau Island for a U.S. immigration permit that may be years away. He and 2,000 other Vietnamese refugees, all single males over 15 years old, are stuck in one of the British colony's new "closed camps," which in this case they share with 1,000 convicted drug addicts.

In Thailand, four Vietnamese Army defectors at the Phanat Nikhom refugee camp tried to commit suicide earlier this month when their applications to emigrate to the United States were rejected.

From Vietnam to the sprawling refugee camps of Thailand to the cramped, often depressing holding centers of Hong Kong and Macao, a growing sense of hopelessness seems to be settling in among Vietnamese who have fled their homeland and those who want to leave.

Many of the refugee camps have assumed an air of permanence as the years have slipped by. And the host countries of the region are taking a tougher line on new arrivals as resettlement opportunities in the West dry up.

Faced with high unemployment and economic recession, the United States and other resettlement countries have wearied of the refugee problem and have sharply cut back their intake. Alarmed by the trend, some of the region's "countries of first asylum" bitterly accuse the West of reneging on its promises.

In Vietnam, authorities have intensified a crackdown on illegal departures, and fewer people are willing to risk the dangers of escape by boat.

The situation is good news for the Southeast Asian and western countries that unanimously want to staunch the flow of refugees. But it is bad news for the numerous Vietnamese who tell western visitors of their desire to leave, and whose cases seem so hopeless.

The exceptions to the bleak refugee prospects are those who qualify for legal emigration under the U.N.-sponsored Orderly Departure Program, and children fathered by Americans during the Vietnam War.

The largest group of Amerasian children to date flew to Bangkok last week. And U.N. officials hope that, for the first time in four years, the Vietnamese leaving monthly on the Orderly Departure Program will soon outnumber those fleeing illegally by boat.

While western refugee officials say cooperation with Hanoi in these areas has improved, the Vietnamese authorities appeared to pose an obstacle to the Orderly Departure Program when they announced this month that they would reject applicants who were sponsored by Vietnamese who had left the country illegally.

Since more than 550,000 people have left by boat compared to 27,000 under the U.N. program, the number of Vietnamese officially eligible to join relatives abroad would be limited.

In explaining Hanoi's position to a group of visiting journalists in Ho Chi Minh City this month, Nguyen Phi Tuyen, the head of the Vietnamese consulting department for the Orderly Departure Program, said his country was "meeting some technical difficulties" in trying to organize the departure of 40,000 people on Hanoi's list of applicants.

He said that "70 to 80 percent are sponsored by relatives who left the country illegally. Allowing these people to go would be tantamount to encouraging illegal departures. But this does not mean we are not trying to find a solution." Tuyen said another problem was that "we still have 30,000 people granted exit visas but who are not yet accepted by any country."

"We are making great efforts in two directions," Tuyen said. "We are trying to prevent illegal departures and we are trying to find a solution for the people sponsored by those who left illegally. We do consider that the problem of illegal departures is a social reality."

Tuyen asserted, however, that the number of applicants for emigration has declined every year, mainly because economic conditions are improving.

"More and more people have given up their desire to leave the country," he said. "The 40,000 are a legacy from the past. They are victims of hostile propaganda from our enemies."

Western refugee officials say the sponsorship restriction in practice has proved flexible and seems designed mainly to discourage would-be boat people who intend to send for their families from abroad.

But a number of other factors already have been deterring refugee departures and adding to the despair of untold thousands who still want to leave but cannot qualify for legal emigration.

One is stricter enforcement by Vietnamese authorities and, according to western refugee officials, Soviet Navy patrols in the South China Sea. If caught trying to flee by boat, Vietnamese now are liable to spend two or three years in jail, the officials said.

While Soviet ships formerly helped some boat people by giving them food and water, the sources said, they now go out of their way to bring the escapees back to Vietnam. The refugee officials said no Soviet Navy patrols were specially on duty for this purpose, but they are more rigorous than before if they come across boat people.

One reason for the stricter attitude is that authorities are more sensitive about the poor image of Vietnam that the boat people create, western officials said. Another, as one put it, is that "they're tired of losing half their fishing fleet every year."

In fact, a shortage of vessels also has contributed to a 42 percent drop in arrivals of boat people in the region during 1982 compared to 1981. Officials said so far this year, arrivals are running about half last year's monthly average.

Fear of piracy is another factor discouraging would-be boat people, according to refugee officials. It is also reportedly prompting a growing number of those who do leave to buy weapons on the black market first.

Another deterrent is the prospect of long waits in the austere camps that Thailand and Hong Kong have set up.

Recent economic improvements because of pragmatic, incentive-oriented reforms may also have dissuaded prospective escapees motivated by a desire for a better standard of living rather than political considerations.

All in all, said a representative of the U.N. High Commissioner for Refugees, "I am convinced that the days of the major outflow are over." In fact, he added, "in a few years I'm sure we will be helping people to come back to Vietnam. Even now we are receiving some requests for voluntary repatriation. This is our real job."

Other refugee officials maintain, however, that Hanoi authorities still rule out repatriation for Vietnamese who left illegally.

"They're too concerned about fifth columns and spies," one Bangkok-based official said.

Indeed, some western diplomats suggest that this may be one reason that the authorities generally are eager to promote the Orderly Departure Program and curb the numbers of boat people.

"At least this way they know who's leaving," one diplomat said.

Although Vietnamese officials emphatically deny it, some diplomats suggest that the policies may reflect concern about growing anti-Hanoi political activism in what has become a Vietnamese refugee diaspora. According to Hanoi and U.S. officials, 1.5 million Vietnamese are now living abroad, about 420,000 of them in the United States.