On Tuesday, the House Subcommittee on Border and Maritime Security will hold a hearing entitled, “What Does a Secure Border Look Like?” If I were testifying at this hearing, I would respectfully submit to the members of the subcommittee that they’re asking the wrong question. This question has no answer, it’s a diversion from the essential task of creating an immigration system that works for America, and it misunderstands what the U.S.-Mexico border is.

As Ted Alden of the Council on Foreign Relations has pointed out, there are no agreed-upon metrics for assessing the state of border security. The Government Accountability Office and the Congressional Research Service, Congress’s two research arms (which will have witnesses at the hearing), have done useful work in this area. The Migration Policy Institute has published a voluminous and definitive report on immigration enforcement, including the status of the southwest border. All of these studies emphasize the enormous strides that have been made on that border, and the extent to which it looks fundamentally different today than it did 10 or 20 years ago. But none produces the definitive metrics that Mr. Alden argues are urgently needed.

I’m not sure I share Mr. Alden’s enthusiasm for such a venture. In one sense, of course, metrics are absolutely necessary:  They will tell the agencies responsible for the border how they are doing. But it would be naïve to believe that these metrics will end the political debate over the border. This is not a fact-based debate, and the metrics will not make it so. In this debate, as in many these days, those special interests who oppose immigration whole cloth think they’re entitled to their own facts, and they will reject metrics that don’t confirm their beliefs.

In our immigration debate, border security is ultimately a political question, not an empirical one. It is used by anti-reform advocates as a condition:  Until we have it, they claim we don’t deserve an immigration process that works. But most informed people consider creating a commonsense immigration process to be in the national interest. It would produce tangible benefits for our country. Why should we wait until something else, which we can’t even identify, is accomplished before we do something that makes America a better country?

What does a secure border look like? In the real world, where there are no perfect solutions, a secure border looks a lot like what we have now. Staggering sums have been committed to securing the border since the mid-1990s. Nearly 20,000 armed personnel—a five-fold increase in two decades—and almost 300 aircraft now patrol what for most of our history was thought of as a friendly border. An investigation by the Washington Office on Latin America found that so many agencies conduct border enforcement that “managerial and interagency snarls may pose the largest challenge today.” As a result of this huge buildup, according to the Migration Policy Institute, “Border Patrol staffing, technology, and infrastructure have reached historic highs, while levels of apprehensions have fallen to historic lows. Today, there is no net new illegal immigration from Mexico for the first time in 40 years.” A report by the American Immigration Lawyers Association finds that we have already met or exceeded all of the border security benchmarks in previous immigration reform bills considered (but not enacted) in 2006, 2007, and 2010.

Of all the elements of comprehensive immigration reform being debated today, border security is the only one that has already been accomplished, or close to it. We should stop debating this, and get on with the urgent task of creating the immigration system we need.

Finally, the subcommittee’s question reflects a misrepresentation of what a border is. Legally, a border is a line separating geographic or political boundaries—and undoubtedly, all societies seek to control access across it. But functionally, a border is many things, and the U.S.-Mexico border—one of the most complicated in the world—is all of them.

This border lies athwart an increasingly integrated economic community—a community that the United States, Mexico, and Canada have sought to encourage as a matter of policy, which was formalized 20 years ago in the North American Free Trade Agreement (NAFTA). As Tom Friedman noted in The New York Times on February 23, “We do $1.5 billion dollars a day in trade with Mexico,” much of which passes through the border. Millions of people traverse the border annually, the vast majority for tourism or business. Businesses are integrated across the border, with parts of the production cycle occurring on both sides. This economic integration predates NAFTA, which represents more a codification of these trends than their cause. To an extent, the two countries’ job markets have been integrated for decades, with Mexico supplying seasonal labor to the United States.

The border itself has long been a community, reflecting in part the fact that the United States acquired what is now our southwest from Mexico by conquest in the 19th century. Mexican-American families, living in what long ago was Mexico, have extensive family ties across the border. U.S. border cities have sister cities on the other side, which have long constituted communities. Many people live on one side of the border and commute to work on the other. Mexican students commute to U.S. schools. Leaders on both sides have long celebrated this border community; the idea of the border as a protective barrier that separates us is a recent construct.

All of these transactions and interactions are managed across this border—and the well-being of both countries is affected by how well we do it. In light of these realities, to pose the central question as, “What does a secure border look like?” seems somehow divorced from reality. Surely one important function of a border is to control entry, but it is far from the only one. The joint task of Mexico and the United States is to manage this border for the benefit of both countries—and that includes all of the legitimate transactions that occur across it, not just the illegitimate ones.

Contrary to the conventional wisdom that the participants in today’s immigration debate are nurturing, enforcement resources at the border should not be increased. Indeed, they should be reduced, and the funds redirected toward upgrading the overwhelmed ports of entry on the border through which the legitimate transactions in the vast, complicated U.S.-Mexican relationship must pass.