The 2,000-mile long U.S.-Mexican border represents one of this nation's key vulnerabilities to international terrorism. Figures are imprecise, but various authorities have estimated that eighty-five percent of the illegal immigration through that border is by Mexican nationals. It is the other fifteen percent, however, that most worries U.S. security officials. According to Michael Flynn, writing in the 11 December 2005 edition of The Washington Post, on any given day people from nearly 60 countries, "most of whom had hoped to use Mexico as a gateway to the United States," were being held in Mexico City's migrant detention center. The border is so porous that illegal immigrants run little risk in entering the United States from Mexico. While the vast majority of all illegal immigrants may be seeking economic opportunity, as has been claimed, a small number, mostly of Middle Eastern background, also may be entering this country to set up sleeper cells and carry out terrorist attacks. Those opposed to immigration reform reject theea that there is any significant threat posed by the poorly defended southern border, alleging that there is little or no evidence that terrorists would use that route to infiltrate into the United States. But, contrary to such claims and misinformation, the inability of the United States to stop illegal immigration along the border has been recognized by U.S. adversaries for years and has been exploited in a variety of ways. In the second volume of their monumental work based on the KGB archives, Christopher Andrew and Vasili Mitrokhin describe how Moscow Center used Sandinista revolutionaries to infiltrate the United States along the Mexican border and scout out potential sabotage targets. A KGB sabotage and intelligence group, they pointed out, was "formed on the U.S.-Mexican border with support bases in the area(s) of Ciudad Juarez, Tijuana, and Ensenada." Sandinista operatives, disguised as illegal Mexican immigrants, the two authors continued, slipped into the United States and scouted "American military bases, missile sites, radar installations, and the oil pipeline (codenamed START) which ran from El Paso in Texas to Costa Mesa, California. Three sites on the American coast were selected for DRG landings, together with large-capacity dead-drops in which to store mines, explosive[s], detonators, and other sabotage materials. A support group codenamed SATURN was tasked with using the movements of migrant workers (braceros) to conceal the transfer of agents and munitions across the border." While the U.S.-Mexican border is where mass illegal immigration potentially meets global terrorism, the Canadian border with the United States is also a problem, largely because of Canada's inadequate intelligence capability, the lax enforcement of its criminal statutes, and the regular abuse by Middle Eastern extremists of Canada’s asylum program. So what is the answer to improving U.S. border security? Some have suggested the use of more border guards and heightened enforcement, as well as a guest worker program that would seek to manage the flow of Mexican workers, in particular, into the United States. But would that be enough to stem the flow? Most knowledgeable observers say no. What is needed, they maintain, is a barrier like the one Israel has constructed to prevent Palestinian infiltration. Walls, Fences & Barriers Israel's so-called wall is not really a wall but a multifaceted barrier. In some places it is a wall – designed primarily to prevent Palestinian sniping at cars traveling along Israel's major north-south axis road. In other places it is only a fence. The entire barrier, however, is equipped with sensors and alarms designed to detect any movement by infiltrators. The Israeli barrier has been an unqualified success, virtually shutting down cross-border raids and infiltrations by Palestinian terrorists. In fact, it has exceeded the expectations of even its strongest proponents. The United States could construct a barrier, not unlike the Israeli barrier, along its southern border that, if properly installed and administered, would almost completely shut down cross-border illegal immigration. It would not be extraordinarily expensive or time-consuming to do so, and the barrier would not constitute a particularly difficult engineering challenge. In fact, there already is a high metal fence, nearly all of it in urban areas, along about five percent of the border between the United States and Mexico. However, because much of the border is protected by a wire fence only three feet high, illegal immigrants simply avoid the high metal fence and cross the border where it is less difficult to do so. The barrier itself could be constructed of steel, concrete, chain link, or a variety of other materials. It should not be a passive fence but, rather, what is known as an "active" fence and designed to detect and delay illegal entry or even thwart it altogether. It also should be well-illuminated with light poles every sixty feet or thereabouts so that CCTV cameras could relay images of anyone attempting to breach the barrier back to monitors manned by border patrol agents. Consideration should be given, in fact, to building a double fence, with the second fence electrified. The first fence (or barrier), which should be relatively high and topped with razor wire or concertina, would serve to delay the intruder/illegal immigrant(s) and, because it would be configured with sensors, to alert border response units. If an intruder/illegal immigrant nonetheless succeeded in breaching the first fence, he (or she) would be trapped between the two fences and usually unable to get through the second, electrified, fence. The latter would be a non-lethal-pulse electric fence. Wires within the fence would transmit brief high-voltage pulses of electricity that would shock an intruder but not cause permanent damage. The area between the two fences should be about 15 feet wide and could be built in the form of a recessed concrete ditch twelve feet deep, broader at the bottom than at the top, with sloping sides. The walls of the ditch could be coated with a number of lubricants and/or other materials that would make them even more difficult to climb. A Broad Spectrum of Sensors Barrier planners could incorporate a variety of different sensors. Among those they could choose from are the following:
- Point Vibration Sensors: Inexpensive and relatively easy to install, point vibration sensors could be mounted on the barrier to detect disturbances associated with climbing, sawing, cutting, or lifting the fence.
- Ported or “Leaky” Coaxial-Cable Sensors: Ported coax or "leaky" cable detection systems generate an invisible electromagnetic field around two cables that are generally buried in the ground approximately three feet apart. One of the cables transmits signals; the other receives signals. Such sensors, which are most often used where covert detection is involved, could provide an additional level of detection, particularly when coupled with point-vibration sensors.
- Seismic Sensors: Such sensors are particularly useful in detecting tunneling, which has been a continuing problem on both the Mexican and Canadian borders.
- Electrostatic Field Disturbance Sensors: Electrostatic field disturbance sensors generate an electrostatic field between and around an array of wire conductors. These sensors, which detect changes or distortions in the field, could be mounted on the barrier parallel to one another, and to the ground, to provide uniform sensitivity along the entire length of the barrier.
- Microphonic Cable Fence Disturbance Sensors: Sensors of this type are designed to protect fences and barriers against climbing, lifting, or cutting. They are quick and easy to install, comparatively inexpensive, and provide a high probability of detection.
- Advanced “Microstain” Fiber Option Sensing Systems: A microstrain fiber optic sensor is an advanced in-ground or fence-mounted detection system that uses a multi-core fiber that can detect minute vibrations. With a sophisticated signal-processing and analysis system, different types of vibrations can beentified and those attributed to false alarms eliminated.
Larger Response Force Also Needed President Bush recently told the American people that the United States will “return every single illegal entrant.” But it seems obvious that it would make more sense to prevent illegal migrants from entering in the first place rather than having to chase them down and then expel them. A permanent barrier would be not only far more practical and effective, but also more humane. An important key to the success of the barrier would be to have enough border patrol officers, stationed at intervals along the border, to respond quickly and effectively when anyone would try to breach the barrier. Without a timely response effort the whole project would fail. The U.S. Border Patrol recently initiated the use of drones mounted with cameras to patrol the border. Continued use of the drones, combined with CCTV, sensors, and roving patrols, would make it extremely difficult and perhaps impossible for illegal migrants to circumvent the barrier. If it is true, as is frequently alleged, that the U.S. economy needs what are currently described as illegal workers, mostly from Mexico and Central America, the creation of an effective barrier wall could be combined with a guest-worker program, such as the one President Bush has proposed, that would provide a suitable vehicle for legalizing the admission of foreign workers into the United States. Until that happens, though, stopping illegal immigration is perhaps the most important step the U.S. government can take to protect this nation, the American people, and the nation’s economic resources.