HANOI -- Vietnam's efforts to restructure its Communist economy are being complicated by a serious unemployment problem that has been intensified by the Persian Gulf crisis, German reunification and the political transformation of Eastern Europe.

As a result of these developments, tens of thousands of Vietnamese who had been working overseas under a government program to use the country's excess labor to repay foreign debts have lost their jobs. Now they are streaming home to a country where a transition to a market economy had already made jobs scarce.

According to Nghiem Xuan Tue, vice director of the international relations department in Vietnam's Labor Ministry, Vietnam's overseas workers totaled about 200,000 earlier this year, most of them employed in factories in the Soviet Union and Eastern Europe. Nearly 2,000 are working in Libya, he said.

The most serious situation for the overseas workers is in Iraq, where more than 16,000 Vietnamese have been stranded since the Iraqi invasion of Kuwait on Aug. 2.

Tue said that many of the workers have been suffering from weight loss and dysentery since Iraqi authorities cut back their food supplies. He said Vietnam is trying to ship 500 tons of rice to its workers in Iraq and hopes to evacuate 700 of them by sea.

Most of the workers are employed on irrigation and road projects near the Turkish border, Tue said, but others have been working in and around Baghdad and in the southern city of Basra. Among the workers are about 200 female nurses, Vietnamese officials said.

The Foreign Ministry said last month that the workers faced "a serious lack of food and medicine." Iraq had said it would halt food deliveries to the workers on Oct. 1, but later it reportedly rescinded the order.

Calling the situation "critical," the Foreign Ministry has appealed to the United Nations, other international organizations, Western and Asian governments and even the United States for help.

The workers were sent to work in Iraq to help repay about $400 million that Vietnam owes Iraq for oil purchases.

About 60,000 Vietnamese had been employed in East Germany under contracts of five to six years, but now they are being forced to return home by German reunification, Tue said. He said 20,000 would return by the end of the year, and nearly all would be back by June 1991.

An additional 20,000 Vietnamese in Bulgaria are due back by 1992, and 37,000 in Czechoslovakia will be brought home from now until 1995, when the last of the current contracts ends, Tue said. He said about 80,000 working in the Soviet Union are being retained because they are still needed.

The problem of absorbing the overseas workers is complicated by several factors, officials said. Vietnam, with about 65 million inhabitants and a population growth rate of 2.12 percent, is unable to provide the more than 1 million new jobs a year that are needed just to keep up with its growing labor force. Government statistics put unemployment at 1.7 million, but a knowledgeable official said the figure was closer to 6 million.

On top of that, according to Tue, the army has been reduced by 500,000 in a massive demobilization highlighted by last year's withdrawal of Vietnamese forces from Cambodia. The country also faces the prospect of thousands of boat people returning from Hong Kong under a recent international agreement that provides for involuntary repatriation. More than 54,000 Vietnamese are stuck in detention centers there.

Now, with the developments in Iraq and Eastern Europe, Tue said, "we will have all those workers coming back to join an army of people without jobs. That will be a huge and complicated issue for the government to solve."

Even before their current difficulties, Vietnam's overseas workers had periodically fallen victim to a clash of cultures in their East European host countries. According to Vietnamese officials, many of the workers have suffered discrimination and beatings in the Soviet Union and neighboring countries, and gang fights between Vietnamese and local youths have been reported.

Some of the resentment has been stirred by the involvement of Vietnamese in black-market activities, prostitution and other illegal practices, according to reports from Eastern Europe. But much of it seems to stem from xenophobia and racist attitudes, Vietnamese sources said.

In Bulgaria, Hanoi Radio reported recently, Vietnamese workers have been set upon by "hooligans" while police have turned a blind eye. In Czechoslovakia, one official here said, Vietnamese have been attacked by gangs of "skinheads" that have formed there.

"In some East European countries, Vietnamese say they are Japanese to avoid a beating," the official said. "This is very shameful for us."