By Edward Alden

The front page of the New York Times this week (Oct. 12) has re-launched the debate over whether the United States should finally complete the long promised comprehensive entry-exit system as a tool for preventing terrorist attacks. It should be a short debate: the answer is no.

Congress mandated the creation of such a system in 1996, but the first phase was not deployed until the launch of US-VISIT in 2004. The entry system, which added biometric checks, has unquestionably been a positive addition to border security and counter-terrorism, by reducing fraudulent entry and allowing for individuals to be checked against terrorist and criminal watch lists. But an exit system is another matter.

Let’s leave aside the economic impact of exit controls, particularly a biometric, real-time system to match the entry component of US-VISIT. With southbound traffic across the Canadian border already at its lowest level since the 1970s, however, the economic impact of adding exit controls on top of all the other measures is certainly a legitimate issue.

Let’s also set aside the fact that the vast majority of conspirators in terrorist plots aimed at the U.S. homeland have been legal U.S. residents, not illegal immigrants. The Times story focuses on the case of Hosam Maher Hussein Smadi, a 19-year-old Jordanian who came to the United States in 2007 and remained in violation of his visa. Smadi was arrested after he failed to notice that his co-conspirators in a plot to detonate a truck bomb under a Dallas skyscraper were FBI agents posing as al-Qaeda operatives. The story makes no mention of the more serious allegations against Najibullah Zazi of Denver, who is alleged to have trained with Al-Qaeda in Pakistan and been at the center of a plot to emulate the Madrid train bombings in New York City. Zazi is a legal immigrant who has lived in the United States since 1999.

Rather, the biggest question is this: What would authorities do with the overstay information if they had it? There are three possibilities.

First, they could launch a manhunt for everyone who fails to “check out” of the country when their visas expire. That would be an extraordinary undertaking for already overstretched Immigration and Customs Enforcement agents who can’t currently manage the nearly 400,000 illegal immigrants being detained each year. ICE doesn’t even pursue the much smaller population for which an entry-exit system actually exists. In Smadi’s case, DHS would have been aware that he had overstayed since, as a Jordanian, he would have been enrolled as a special interest alien under the National Security Entry-Exit Registration System, or NSEERS. Those who are registered in NSEERS when they arrive are required to leave through a limited number of major airports and record their exit when they depart.

Second, and more plausibly, Washington could develop a comprehensive database so that the record of every visa overstayer is entered into the watch lists or criminal databases available to local law enforcement authorities. That could have some value, but, again, what should local police do with that information? The so-called 287 (g) program which deputizes some local police for immigration duties is already hugely controversial, and most police departments see it as harming their core mission of local crime-fighting.

In Smadi’s case, according to the Times story, he was pulled over early last month in Texas with a broken tail light. When his name was checked, it showed up on a terrorist watch list, but there was no mention of his visa violation. Advocates of entry-exit would argue that U.S. security would have been served had he been arrested and deported. Yet Smadi had been under FBI surveillance since earlier this year. Clearly the reason his immigration status was not divulged in the watch list entry is that the FBI didn’t want some gung-ho Sheriff Arpaio arresting him and screwing up the investigation.

Finally, and most plausibly, a comprehensive entry-exit system could be a useful investigative tool for the FBI. That is, if a name came up in a terrorism investigation, and it was known that the individual had entered the United States on a legal visa, it would be helpful for authorities to know whether he had left the country or not.

But to confront the enormous logistical difficulties of creating a comprehensive entry-exit system for such minimal investigative benefits doesn’t make a shred of sense. When Michael Chertoff was DHS secretary, he looked at the problems and concluded that it simply wasn’t worth the costs. And Chertoff was no softie on terrorism. Chertoff’s policy chief, Stewart Baker, put it correctly in an interview with me last year. Exit controls, he said, are about creating “an immigration accounting system. It’s less about safety and more about immigration record-keeping.”

There can certainly be reasonable arguments that the integrity of our immigration system requires such rules. But this shouldn’t be confused with preventing terrorist attacks. An exit system will contribute nothing to that goal.

Edward Alden, a senior fellow at the Council on Foreign Relations, is the author of The Closing of the American Border: Terrorism, Immigration and Security Since 9/11.