When the Border Patrol gives their presentation about the border wall, the first slide they show is a photograph of the burning twin towers. When they approach landowners to discuss using their property to build the wall, they hand out leaflets emblazoned with this disturbing image. But the fact is that a border wall will do nothing to protect us from a terrorist attack, and even an impenetrable wall built across all our land borders would not have prevented the tragedy on September 11, 2001. By using this rhetoric, the Border Patrol, the Department of Homeland Security, and proponents of the wall are not only manipulating the public by playing on their fears, but they are also falsely transforming the economic issue of immigration into an issue of national security.

None of the al-Qaeda terrorists who committed the 9/11 attacks entered the U.S. illegally from Mexico or Canada. Instead, they flew into the country legally as students or tourists and then violated the conditions of their visas. Indeed, the only terrorist apprehended at a land border, the would-be Millennium Bomber, was attempting to enter the U.S. through Canada, not from Mexico.

The real reason that the federal government wants to build a wall along our southern border is not to keep out terrorists, but to stem the tide of immigrants entering the U.S. illegally in search of jobs. These immigrants, usually among the poorest in the hemisphere, are not people we need to be protected from. Instead, we need a level-headed solution for illegal immigration that takes into account all of the social and economic complexities that surround the issue. Walling up the border is not that solution.

The most obvious reason that a border wall won’t work is that, like the 9/11 hijackers, up to 50% of people residing illegally in the U.S.entered legally through ports of entry. And despite several initiatives authorized by Congress since the 9/11 attacks, the federal government still has no way of determining whether people admitted to the U.S. for temporary stays actually leave the country. A border wall would have no effect on this situation.

A border wall will not stop immigrants who enter the country illegally by crossing land borders either. Physical barriers can be climbed over or tunneled under, as Homeland Security Secretary Michael Chertoff has admitted, and Border Patrol has said that the wall will only slow someone by five minutes. It is far from an impenetrable barrier. Nevertheless, the existing wall near San Diego has resulted in a reduction of Border Patrol apprehensions in that sector, leading some to champion its effectiveness. However, overall the number of apprehensions along the southern border has remained the same. Instead of halting crossers at the border, the San Diego wall has funneled them into more remote desert areas in Arizona.