One third of the forty-eight al Qaeda operatives who committed crimes in the U.S. between 1993 and 2001 were residents or citizens, while another third had visas. They obtained them because the countries where they originated their travel were not on the list of sponsors of terrorism. In a world in which terrorism is a moving target, every country is a potential source. How would, say, a million border agents and a tiny quota allowing foreigners to work and live in the U.S. have stopped these people from coming in or obtaining residence/citizenship?
Even a fortress America would not have prevented the attack on the Boston marathon since the perpetrators were raised in this country. Again, this was an intelligence and law-and-order failure: one of the terrorists had been questioned by the FBI. They were not linked to terrorist organizations and they developed their radical beliefs in the United States. Is it reasonable to expect immigration policy to anticipate who will develop radical anti-U.S. beliefs decades after settling in this country? Can immigration policy prevent anybody from learning how to build an explosive online?
Surely a flexible, realistic immigration policy that does not generate illegal entries is a better way of making sure everyone operates within the law and of helping counterterrorism policy separate the law-abiding wheat from the terrorist chaff.
Alvaro Vargas Llosa is a senior fellow at the Independent Institute and author of the new book, Global Crossings: Immigration, Civilization and America.