President Bush's immigration reform proposal-the centerpiece of which would be to grant legal status to millions of undocumented workers in a "temporary worker" program-has a number of flaws.

Such programs have been tried, not only in the United States, but in Western Europe.  Without exception, they have never worked as promised.  Instead of facilitating the temporary residence of workers, they have ended up creating millions of permanent residents and bureaucratic nightmares.

The president's plan runs the risk of creating an Athenian-style "metic" class-where millions of guest workers enjoy legal status and some labor rights but are disenfranchised as well as disconnected from the communities in which they reside.  And those who believe that Mexicans legalized under this program would eventually take the fruits of their labor and return home need to study closely what happened with similar programs in France and Germany.  There, "guest" workers from North Africa and Turkey became permanent residents; human rights and immigration advocates lobbied for amnesty and family reunification, so that young men who were supposed to go home instead brought "home" with them.  That will surely happen here.

Unless President George Bush wrings joint responsibility for our current insecure border from President Vicente Fox in Monterrey, Mexico on Monday, his immigration proposal will amount to a rank bid for cheap votes and cheap labor. And because the proposal could muddle the president's messages of homeland security and limited government, it may not even pay the anticipated electoral dividends.

But what leverage will Bush retain in Monterrey now that he has already unveiled his "bold" immigration proposal? Actually, the President kept his most of his powder dry by leaving open the terms of his proposal. There will be a fee for becoming legal and a spell as a temporary worker before permanent residence. But how high the fee and how long the spell?  How many temporary workers will be accepted? And how many promised new immigrant visas will be made available, and of those what will be the Mexican share? All that will depend on negotiations with Congress. Will the President be content to claim credit with Latino voters for his "bold, new proposal," while he lets it languish in Congress?

There is a security dimension to what Mr. Bush is proposing. The presence of some 8 to12 million illegal aliens creates a huge market for fraudulent documents. Several of the 9/11 hijackers procured phony credentials from Salvadoran immigrants. Moreover, there is nothing to prevent alien smugglers from packaging terrorists among other illegal border-crossers.  Not only does the presence of millions of undocumented workers create an "underground" within the United States that can be exploited by terrorists and criminals, continued smuggling of illegals across the border create routes that can be used not only by those seeking a better life in the United States, but those interested in bringing in deadly cargoes (whether drugs or dirty bombs) undetected.

Bush's announcement gives him some leverage with Fox, that in return for considering some form of legalization for undocumented Mexicans already living and working in the United States, the Mexican government would be willing to take joint responsibility for border security.

Any proposal with a chance of controlling illegals depends on securing the Mexican border. We have tried to do that unilaterally through an array of fences, cameras, sensors and patrols. These measures have channeled rather than stemmed the flow of illegals. It has driven migrants away from urban areas into the desert (and encouraged professional alien traffickers) leading migrants to perish in the desert.

Mexico could stop jeopardizing the lives of its citizens by putting those dangerous zones off-limits, obliging travelers to depart solely from authorized ports of exit. If those ports were placed opposite zones currently patrolled on the American side, the two countries could make the border safe and secure and put some teeth in the Bush proposal whose first principle is that "America must control its borders."

In the past, Mexicans insisted that Article 11 of the Constitution which guaranteed the right of free travel prohibited such measures, even though the article makes it clear that the state has the power to regulate the exercise of this right.  When President Bush meets with President Fox at the Summit of the Americas, he can make it clear that any amnesty/legalization plan has no chance of passing the Congress unless the border security concerns are addressed.

Mexican federal officials and state governments quietly have indicated willingness to undertake those politically unpopular exit measures if their migrants can become legal in sufficient number. Bush must gain Vicente Fox's commitment to monitored border responsibility at the Monterrey economic summit next week.

The course of joint responsibility is the preferable one because the other option-- deporting illegals and unilaterally securing the border - would be an administrative long-shot and a sure guarantee of Mexican enmity. The last thing we need is a hostile southern neighbor unwilling to help guard against terrorist infiltration.

And for this program to work, it must be attractive enough for current illegal immigrants to choose to register and come forward to be documented and registered, to eliminate that security risk-but not to create incentives for new immigrants to cross the border to take advantage of its benefits.  This is where the border security component comes in.  And joint responsibility offers a real way to put teeth behind enforcement measures.

This cannot stop, however, with an immigration deal.  Ultimately, reducing cross-border flows depends on Mexico's own continued economic development.  Mexico must continue to pursue a whole host of fiscal, labor and energy reforms that will encourage further capital investment. (Indeed, given California's own growing energy crisis, one could envision a more symbiotic relationship where increased investment in a reformed and privatized Mexican energy sector could produce additional supplies for a starved California market). 

But getting a deal on immigration-that makes the border secure-is an important first step.

Robert S. Leiken is the director of the Immigration and National Security Program at The Nixon Center.