How secure is the border? The opinion of government optimists is that it is way secure. So secure you wouldn’t believe it — and not as secure as it will be.

That is the least the country should expect after all it has given up to lock the border down. Billions of dollars since the 1980s in fencing, razor wire, electronic sensors and vehicle barriers. A major deployment of 6,000 National Guard troops in 2006, to bolster the Border Patrol. The trashing of the Endangered Species Act, the Clean Water Act and a host of environmental and land-management laws. (When Congress ordered the homeland security secretary, Michael Chertoff, to build 670 miles of border fence by the end of this year, it decreed that no law or judge, no wild creature or endangered homeowner, should stop him. Last month, the Supreme Court declined to intervene in one of the many legal disputes the fence has provoked.)

The National Guard is leaving the border at the end of the month. And even though the border states want them to stay, the Bush administration is declaring victory. That’s how good things are down there.

Too bad, though, that the results that restrictionists predict from victory — an end to illegal immigration, the expulsion of illegal immigrants, the restoration of jobs to American workers, the protection of American culture and language from a Hispanic invasion — are not coming anytime soon. That’s because fixing immigration has very little to do with any of the hustle and bustle along the 2,000-mile line from San Diego to Brownsville, Tex.

The Center for Comparative Immigration Studies at the University of California, San Diego, recently did the radical thing of talking to border-crossers about why and how they come. In a survey of undocumented immigrants from four Mexican states, it found that fewer than half are caught by the Border Patrol. Those who fail the first time try again and again, and their success rates for entering the country hover consistently above 90 percent. Sheriffs, police officers and elected officials in border communities — some of whom have ridiculed the fence and sued to block it — would readily confirm that.

The study offered another compelling example of enforcement gone awry: reports that illegal immigrants who are stymied by a tighter border are staying put, setting down roots and bringing their families over.

This is not to argue for giving up on enforcement. The real victory will come when a repaired, well-patrolled border coincides with a repaired, well-run immigration system that requires undocumented workers to come forward and be legalized, has expanded avenues for legal workers, including would-be citizens, and cracks down on illegal hiring as staunchly as it protects workers’ rights.

There is a long list of things to do to make the immigration system correspond to American values and economic realities, and the country is doing just about none of them. We’re paying a huge price to pay for an ineffective fence and some symbolic victories on the border.