Twice a day in the Washington Hilton's Colonial Room, Trudy Schlegel, a German by birth, throws her multinational troop into action.

Jamaican, South American, Haitian, Barbadian and Southeast Asian employes rush about polishing flatware and folding napkins, straightening chairs and smoothing tablecloths.

Over at the dining room entrance, German, Swedish and Thai hostesses sort through the day's menus and wait for the arrival of the first customer.

Altogether, 26 of the 41 waiters, waitresses, hostesses, bus men and women are immigrants.

They gave different reasons for being here. Some have come to Washington because of marriage, others to escape war, many because the availability of jobs and salaries is unmatched in the land of their birth.

A common threat ties almost all of them together in the eyes of their employer. As different as the countries from which they come, foreign workers tend to bring with them to the United States a sense of possibility and perseverance -- a faith in the ability to get ahead through hard work, no matter what kind of work it is. If this were another century, this faith might be called the Protestant ethic or the pioneer spirit.

What it amounts to now -- and indeed what it may always have been -- is the immigrant ethic.

"I think," said Schlegel, "these foreign workers have a bigger sense of what they've lost or left behind and what working here can mean to them. If you give these people a chance, they work twice as hard as Americans."

The reason is simple. Hard work -- witness Schlegel, who was recently promoted to assistant director of Hilton's food and beverage section -- is the way to get ahead.

In restaurants, hotels, building maintenance firms -- wherever, in fact, one finds low-paying jobs with little or no status -- the men and women who do the hiring are saying the same thing: foreign workers are preferred because they are the best bet to work hard and work without complaint.

"It's just like when the Irish and Italians and East Europeans came here," said Stephen L. Raab, president of the New Yorker Bakery in Northwest Washington, where a number of Cambodian refugees work. "These people are willing to start at the bottom and work their way up. The American public has basically had everything too easy. They don't know what it is to suffer."

Or perhaps it is only that Americans who might have taken such jobs because of youth or poverty or lack of education have grown up in a society where expectations are built so high that not working at all seems better than starting at the bottom and running the risk of staying there.

"Many of our youngsters here in Washington have a feeling that they can determine what they'll do and how hard they'll have to work," said Adolph J. Slaughter, a D.C. Labor Department spokesman whose agency is charged with helping unemployed local residents find jobs. "It's a whole change in attitude that happened in the last 20 years, especially in the minorities.

"Jesse Jackson is telling these kids to say 'I am somebody.' That's good. But the kids are saying, 'Well, if I'm somebody, I don't have to wash no damned dishes.'"

At the same time, they are likely to be saying, "Those foreigners are taking our jobs."

The new immigrants have culture and traditions and physical attributes that differ markedly from familiar American norms. As these new faces are seen to compete for work with native-born Americans in an economy staggered by inflation and unemployment, tensions inevitably arise.

"It really p--- me off." said a man standing in the lobby of the D.C. Labor Department. "I got a son who can work as good as any of those Mexicans, but they don't hire the blacks. They want those guys who don't give them no s---. So he can't get no job because all they want are guys like that. 'Wetbacks,' isn't that what they call them?'"

"Wetbacks," or illegal aliens, are a favorite target for those who resent the growing foreign presence in the job market.

Some immigration investigators will guess, though they have been directed not to do so because there is no statistical foundation for it, that there are 100,000 foreign workers in the metropolitan area and half of them are illegal.

Politicians usually are careful to distinguish between the job threat posed by illegal aliens and the legitimate right-to-work of legal foreign residents and foreign-born citizens. The general public is not always so cautious.

"We got calls from people, many of them seemed to be black," said Russell G. Parry, a former immigration investigator here in Washington. "An individual will go into a place of business and ask for work and all he'd see are people who don't speak English. He'd get mad and call us" to tip off the investigators that illegal aliens may be working there.

"They may call five or six times," Parry said. "We'd get about 60 such calls a month."

The underlying assumption of the callers is clearly racial -- foreign-looking or sounding is likely to mean illegal. Even trained immigration investigators have difficulties specifying exactly what a typical illegal alien looks like, and have run into repeated trouble with the courts for using warrants that describe illegal aliens in such a way that virtually any newly arrived, dark complected, non-English-speaking immigrant, whatever his status, could fit the bill.

Latins bear the brunt of the prejudice, but Asians also often find themselves suspect, and all are quick to voice their resentment.

When Councilwoman Wilhelmina Rolark proposed a bill two years ago that would have made it a crime to hire an illegal alien in the District of Columbia, she found her hearing room suddenly overflowing with angry opponents. Americans of Hispanic, Philippine, and Oriental ancestry united to fight a law that they feared would worsen the already considerable discrimination they felt they face in the job market. The bill quietly died.

You don't have to be Hispanic to be illegal, as the witnesses at the Rolark hearing testified. All you have to do is let your visa expire and get a job. Noted British journalist Henry Fairlie was an illegal alien living and working for several years in Washington before finally turning himself in to immigration and getting a proper visa. Another man, a West European who administers a large federally-funded program with a salary in the neighborhood of $30,000 recently told a reporter that he, too, was illegal.

Yet, once one gets past the prejudice, real problems remain.

The crucial question, to which there is not yet an authoritative answer, is whether illegal aliens, or for that matter, legal ones, take a significant number of jobs away from Americans who want them.

On the national level it is argued that foreign workers, especially illegal aliens, are willing to work under worse conditions for lower pay than Americans, and that therefore the aliens are being exploited. That clearly has been the case in a number of industires and on many farms, especially those close to the Mexican border.

But there is no substantial evidence of many foreign workers in Washington receiving less than the minimum wage. In the cases that have turned up of aliens being exploited, the employers also had a tendency to cheat their American workers.

Employers of foreign workers in and around the District of Columbia constantly point to the immigrants' reliability and their reluctance to complain. In the case of illegal immigrants, the reluctance may be fostered by their fear that they will be deported if they make trouble. Indochinese workers are noted for the same attributes, and virtually none of them have come illegally.

D.C. Labor officials say their experience tends to support the contention that Americans no longer are interested in many jobs.

When a business seeks to employ a foreign worker legally, it first must obtain permission from local and federal agencies. The job opening must be advertised in local newspapers in case any qualified American is interested. If there is a qualified American applicant, he must be hired rather than the foreigner.

Jobs advertised in the past have ranged from menial employment, like dish washing and live-in domestic workers, to computer specialists, nurses and other prestigious positions.

"It's almost as if people aren't reading classified ads," said Charity Merritt, a D.C. labor department official. "You'd think you could fill them."

For businessmen like Raab, of the New Yorker Bakery, who numbers several blacks on his payroll ("They take pride in their work," he says), the answer seems plain.

Americans "think we owe them a living," he said. "But the reason there are more and more immigrants getting those jobs is simple: it's survival of the fittest."

The workers themselves, as they tell their stories, give rather more humble reasons for their dedicated labor at whatever jobs they can find.Survival remains a key element.

"I come here because if you are going to get a [well-paying] job in my country you have to have a good education," said Edie Vanasiri, a Thai who works in the Hilton's Colonial Room. "Here you don't have to. You can be a street cleaner and earn a lot of money."

Another woman, here illegally and who asked not to be identified, said: "In Colombia we lived in a very poor village.When my husband died, there was no one to take care of my family. I came here because I heard I could make a lot of money. There were no jobs for me in my country."

Now the woman holds down two jobs, both at the bottom of the American economic ladder. During the evenings, she works for a maintenance company that cleans the office buildings ocupied by prominent Washington attorneys. During the day, she works in a restaurant, one of Washington's most fashionable, washing dishes and scraping plates.

At the end of each month, she sends $400 to her eldest daughter who takes care of the woman's four other children and elderly mother. The woman keeps between $125 and $150 a month, living in a cramped apartment near Washington's Columbia Road. She shares the apartment with another woman working similar hours. She said she will stay as long as she can.

"We would starve if I did not come here," she said.

Other foreign workers, having passed survival stage, have old-fashioned success stories to tell.

Juaquin Chaivez, a Mexican who works on Metro construction, said he now earns about $20,000 a year. In Mexico, doing the same sort of work, he said he would be lucky to make $4,000.

Chaivez came to the United States at age 15. "I washed dishes, mopped floors in Los Angeles for a couple of years," he said. "I spoke no English, I decided I would come out here to see what I could earn."

Now he owns a duplex in Rockville where he, his wife and child have achieved a true American lifestyle.

If the Chaivezes were successful in attaining the American dream, at least one study shows that they are not the exception.

According to a study by Barry R. Chiswick, a professor at the University of Chicago, those who traditionally have viewed foreign-born men as a drain on the American society may be mistaken. He found that, while they are most likely to earn less than native-born men initially, over a period of time they eventually catch up and may even surpass their native competitors.

Further, according to his research, those whose parents were foreign-born -- first generation American -- tend to earn more than those born of native American parents at most levels.

Chiswick's findings are challenged by some. It is known, for instance, that Hispanic families in the U.S. lag substantially behind other families in income. Michael J. Piore, of the Massachusetts Institute of Technology, has found that the children of immigrants who start at the lower end of the economic ladder often are little better equipped than their parents to advance beyond or even equal their parents.

"If those findings are correct, what will happen to the children of today's immigrants?" asks Piore. In another generation, it may be they who came back to haunt America.