Peek into any US hotel or restaurant kitchen, and you are likely to spy foreigners without green cards through the dishwasher steam. These workers are known as illegal aliens or more benignly as undocumented workers, depending on your view of the issue. Foreigners authorized to work in the US can also be found in garment factories, tomato fields, parking garages, taxicabs, behind a broom, and performing a host of other tasks whose common features are long hours, scut work, and low pay. Millions of such workers continue to flood the labor force despite a long-fought 1986 immigration-reform law that liberalized legal immigration in exchange for what was supposed to be a crack-down on unlawful entry and employment.

The novel idea of the 1986 law was to hold business accountable for hiring improperly documented workers. But the law had to be watered down to win enactment because of opposition from employers who justifiably resisted being deputized as border guards, and from civil rights groups with legitimate fears that anyone with a Hispanic surname or Asian features might be subjected to the third degree. In practice, an employer need only make a reasonable effort to examine a worker's documents - a Social Security card will usually do - and the employer is legally off the hook. But of course, such documents are notoriously easy to forge or misuse.

LONG HOURS

In the real world, according to a source in the restaurant industry, the system works like this An unauthorized immigrant job applicant produces either a borrowed Social Security card or a forged one. Other corroborating fake IDs are even easier to get. The worker then claims a very large family - so many that no withholding is taken out of his or her paycheck. My source says he doesn't know - or care - which of his employees are working under their own names, which ones are citizens, or which ones are aliens. What he does know, he says, is that they are all hard workers. Many of them work the breakfast shift in one restaurant, the day shift at another, and even dinner at a third. Living collectively and working a 14- or 16-hour day, they can make close to $1,000 a week, effectively tax-free except for deductions for FICA (Federal Insurance Contribution Act). Most of their earnings are sent home to El Salvador or Colombia. Or Nigeria, or Ireland, or China, or Haiti, or Mexico, or wherever.

What are we to make of this? In a sense, there is a crude social bargain here. The unauthorized workers enjoy the benefits of US residence without paying US income tax. US consumers and employers get the benefits of these hard-working foreigners, whose wages - though low - are infinitely greater than they could earn in their homelands.

On the other hand, foreigners receive no benefits from payroll deductions credited to bogus Social Security numbers. Also, billions of dollars worth of wages are sent out of our economy, rather than going to purchase goods and services here. And hard-won benefits to American workers - minimum wage, the eight-hour day, pensions - are undermined by the enormous underground economy.

AMBIVALENCE

Recently, the Immigration and Naturalization Service announced the latest in a series of futile crackdowns. In the past four months, approximately $3.2 million in fines have been imposed on employers for hiring obvious illegals. But that's about a dollar for each of the estimated 2 million to 4 million foreigners working illegally in the US. For the entire country, the INS has only about 1,800 special agents working in non-border areas, with several hundred of them devoting their time to other matters, such as smuggling or fake marriages.

The deeper problem, I suspect, is a profound public ambivalence about the entire question. With the exception of native Americans, we are a nation of immigrants. Some of our parents and grandparents sneaked into this country and went on not only to thrive but to give a good deal back. In the 1960s, when liberals were indignant about illegal immigrant workers, conservatives responded that such workers were more of an asset than a drain on the economy. That debate continues. Some have even argued that our borders should simply be thrown open.

Moreover, Americans also have a pathological distrust of government identification cards. Until recently, Social Security cards carried the utterly disingenuous disclaimer For Social Security and tax purposes - not for identification, even though Social Security numbers are now in standard use for driver's licenses, bank accounts, insurance policies, passport applications, and so on.

If America were more adult about this issue, like some Western European nations, we might save ourselves endless inconvenience by establishing a single official ID. Employers could ask to see it, and counterfeiting it would be a serious crime.

That way, Americans might finally decide just what sort of immigration policy they really want and have that policy enforced. The current situation, while randomly helping a number of lucky individual migrant workers, has the corrosive side effect of eroding the rule of law.