A tough question: Can 12 million immigrants belong?

What have Americans learned since 9/11? The question has filled the media everywhere this month. Answers, both institutional and personal, have been insightful, and we have likely learned as much from them as from the attack itself.

One lesson near the top of the list is not new: eternal vigilance really is the price of our free and democratic society. It's plain now that not only the shock troops of a distant al-Qaida threaten us, but 'home-grown' terrorists from much nearer at hand do as well. So all of us must be prepared to stand up daily to the danger.

If everything since 9/11 has indeed been changed for America, so too is the way we must adjust and tune our democracy to meet these threats. I'm thinking here not only of the arguments in Washington over our constitutionally guaranteed rights to privacy and due process.

I'm thinking more, in fact, of democracy, the Constitution and the Mexican border.

The arguments over immigration are partly about our national security, indeed. But the alarm is also over the pragmatic, in some places urgent, problems of community. Are we losing jobs; are we overstretching our social support network? Are all illegal immigrants here, farmworkers as well as drug smugglers, equally criminal? Can anything effective be done about it - or is it a 21st-century reality to which we must somehow adjust?

Yes, there are many ways to look at the problem. Estimates differ, but roughly six out of every 100 Mexican nationals now live illegally in the U.S. Some 850,000 of them arrived just in the past five years; the flow increased, the Mexican government confirms, by 20 percent in the first quarter of 2006. Border illegals of many nationalities are moving far beyond their points of entry, to ever-newer and further-flung centers of employment, both small and large - places like shattered New Orleans, for example, where cheap labor is in enormous demand.

We cannot safely allow this to go on, and we cannot afford it. In a San Diego Congressional conference this summer, the national cost to taxpayers was guessed to range above $1 billion per year, just in public schools, hospitals and the justice system. Displaced U.S. workers would certainly insist the total figures run higher.

We cannot just round up 12 million people, most of whom we can't even find (40 percent of them do not sneak into the U.S.: they enter legally and overstay their visas wherever they end up), and tell them to go home.

Declaring all of them felons, as one Congressional bill proposes, would be something abhorrent under our Constitution: the creation of an ipso facto criminal class, defined by the lack of possession of a single document.

More than just the problem of conducting 12 million separate criminal trials when they are caught and their lawyers demand their rights to a defense, we aren't sure what this itself would do to our security. Would a wanted felon shoot a police officer to escape? Would he or she commit further crimes to remain hidden, or to send back home as much illegal gains as possible before capture? Would a vengeance-minded conspiracy of felons feeling the hot breath of imminent capture poison our food supply, in the very places where we employ them - becoming a terrorist threat themselves?

Hold on - we're coming at this the wrong way. It's for sure that once here, illegal immigrants have, and continue to, become parts of our communities. How many more immigrants join them each day by risking their lives to cross the border? How many more will come if the volatile political situation we see now in Mexico boils over into rebellion or recession? How many of these would then have arguable legal rights to claim refugee status when here?

They are in our communities, after all, because our government, as with all other American immigrant groups, has in fact allowed them to enter, in this case through benign neglect. They have been more or less allowed illegal entry for so long because the low wages they earn, and their inability to use everyday rights to protect themselves from abuse, in fact make them a commodity - subsidized labor - for employers large and small.

No more than a slave, no human should be just an economic commodity. Instead of punishing illegal immigrants, we could be more constructive by thinking of all this as a problem of protecting America while making our democracy stronger to meet the new demands of post 9/11.

The illegal immigrants want the privileges and benefits of American prosperity. As we cannot, for now, return them all or even do a great deal to stop more from flowing in, let's think about getting them to also commit to the obligations and responsibilities of living in America.

Let's put them on work permits under our present visa system. If they pay a criminal penalty for their illegal entry, let's put them on the regular track to green cards once the penalty is extracted, even to eventual citizenship, under the same requirements for legal immigrants.

Meanwhile, let's engage them in reporting the soaring border and community drug-smuggling and -trafficking.

Let's motivate them to report suspicious activities of illegal-entrant as well as "home-grown" terrorist plotters.

Let's get them to spot and notify their communities of public-health problems, such as potential pandemic outbreaks, when they become visible around them.

Just think: millions of new agents for our national and community security, instead of millions of nameless unidentifiables just trying to stay off the radar.

Let's guarantee them the right to negotiate their own wages.

Then, let's make them all taxpayers, and fee-based users and capitalists and property-owning stakeholders.

Let's make them social volunteers, crime-watchers, contributors to their own communities, crossing guards and blood donors. Let's employ them as attendants, aides and health assistants for our burgeoning population of institutionalized and at-home care seniors.

Let's do this by using the same visa and criminal-justice systems we already have to sort good from bad; let's make them felons only when they violate the terms of those systems.

The framework for all these answers is already in our Constitution. And no one will ever have to print a ballot in Spanish to achieve this.

Mexico and America have the largest gap in income levels of any two contiguous nations, it is said. We cannot seal off, or move away from, our neighbor. Or its neighbors.

Manage and protect the border, to whatever extent the government can, for certain. But meantime, let's use our democracy to convert all we can of the millions more aliens, either here or planning to arrive across that border, into new defenders of the security and democracy and communities of America in the post 9/11 age.

• Robert Cutts is a career journalist who has been a news reporter, magazine writer and editor; author of two nonfiction books and a college journalism teacher. He lives in Gardnerville and Japan.