Within INS, the Border Patrol is the agency responsible for securing the border between the ports of entry. The Border Patrol’s mission is to maintain control of the international boundaries between the ports of entry by detecting and preventing smuggling and illegal entry of aliens into the United States. In addition, in 1991, ONDCP designated the Border Patrol the primary agency for narcotics interdiction between the ports of entry. To accomplish its mission, the Border Patrol (1) patrols the international boundaries and (2) inspects passengers and vehicles at checkpoints located along highways leading from border areas, at bus and rail stations, and at air terminals. The Border Patrol uses vehicles and aircraft to patrol areas between the ports of entry and electronic equipment, such as sensors and low-light-level televisions, to detect illegal entry into the country. The Border Patrol carries out its mission in 21 sectors. Nine of these sectors are located along the southwest border with Mexico. As of September 30, 1994, about 3,747 agents were assigned to the 9 sectors, representing 88 percent of Border Patrol agents nationwide. The following other federal entities support land border control efforts between the ports of entry along the southwest border. El Paso Intelligence Center (EPIC), the nation’s principal tactical drug intelligence facility, prepares assessments on the threat of drug smuggling. Operation Alliance prepares border control strategies and coordinates drug enforcement activities of 17 federal and numerous state and local law enforcement agencies combating drug smuggling. Joint Task Force Six (JTF-6), located in El Paso, coordinates military support for drug enforcement efforts. In September 1991, ONDCP tasked Sandia National Laboratories, through INS, to do a “systematic analysis of the security along the United States/Mexico Border between the ports of entry and to recommend measures by which control of the border could be improved.” ONDCP chose Sandia because of its expertise in designing physical security systems. In January 1993, Sandia issued its report entitled Systematic Analysis of the Southwest Border. We refer to this as the Sandia study throughout our report. According to the study, to conduct its analysis, Sandia personnel visited all nine Border Patrol southwest border sectors, toured various Border Patrol facilities, and interviewed both chief patrol agents and Border Patrol agents. They viewed much of the southwest border from either the ground or the air and reviewed a number of previous studies related to border control. In addressing our objectives to (1) determine the extent of the threat from drug smuggling and illegal immigration and (2) identify ways to enhance security between the ports of entry, we interviewed intelligence officials responsible for determining the threat from drug smuggling and illegal immigration and reviewed related documentation; reviewed the Sandia study and discussed the study’s findings with its authors and various INS officials responsible for border control; reviewed EPIC, Department of State, and Operation Alliance reports to determine the threat from drug smuggling; visited the San Diego and El Paso Border Patrol sectors and discussed with sector officials their recent border control initiatives; analyzed INS data from its management information systems related to apprehensions and narcotics seizures to obtain additional information on the threat from drug smuggling and illegal immigration along the southwest border; and interviewed INS headquarters officials to determine plans for improving border security. As agreed with the Subcommittee, our focus was control of the land border between the ports of entry. We did not evaluate border control activities at the ports of entry or efforts related to smuggling by air and sea. We did not verify the accuracy and completeness of the data we obtained from INS’ management information systems. We did our work between October 1993 and September 1994 in accordance with generally accepted government auditing standards. We discussed the results of our work with the Acting Chief of the Border Patrol and other INS officials. Their comments are presented on page 27. Although the full extent is unknown, drug smuggling is a serious threat along the southwest border. The Department of State’s 1993 International Narcotics Control Strategy Report indicated that Mexico is a transit country for South American cocaine destined for the United States and a major country of origin for heroin and marijuana. According to the report, between 50 and 70 percent of the cocaine smuggled into the United States transited Mexico, entering primarily by land across the southwest border. In addition, about 23 percent of the heroin smuggled into the United States originated in Mexico. INS data showed that Border Patrol narcotics seizures along the southwest border have risen over the last few years. Between fiscal years 1990 and 1993, the number of Border Patrol narcotics seizures rose from around 4,200 to around 6,400, an increase of about 50 percent. The amount of cocaine seized nearly doubled from about 14,000 pounds in 1990 to about 27,000 pounds in 1993. According to a June 1992 Operation Alliance report, the primary smuggling route across the southwest border was by land. The report pointed out that although cocaine was the primary drug threat, followed by marijuana, the heroin threat was growing. The report stated that in spite of law enforcement agencies’ efforts to counter drug smuggling, the flow of drugs between the ports of entry along the southwest border continued due to vast open areas and a relatively low law enforcement presence. The report concluded that “our successes are insignificant when compared to the threat. Our collective efforts are currently only a minor irritant to the smugglers.” The Sandia study deemed drug smuggling a serious threat all along the southwest border. For example, the study deemed drug smuggling a serious threat in south Texas and the southern Arizona border area, which is dubbed “Cocaine Alley.” Figure 1 shows the seizure of over 1,000 pounds of cocaine by Border Patrol agents in San Diego. Figure 2 shows a panel truck stopped by El Paso Border Patrol agents (see fig. 2A), with narcotics hidden in its interior panels (see fig. 2B). Agents seized nearly 250 pounds of marijuana (see fig. 2C). Illegal immigration is also a serious threat to the United States. In 1993, we estimated that the total inflow of illegal aliens into this country in 1988 ranged from 1.3 million to 3.9 million. The major component of the inflow, 1.2 million to 3.2 million, was Mexicans crossing the southwest border, with most entering between the ports of entry. Much of the inflow represented short-term visits to the United States. In June 1994, INS estimated there were about 3.8 million undocumented migrants residing in the United States. About half of the unlawful residents entered unlawfully across the borders, while the other half entered as visitors but did not leave. The estimates were based on an analysis of INS and Bureau of the Census data and, according to INS, experts have embraced these estimates as the best available. The 1993 Sandia study characterized the southwest border as “being overrun.” For example, in the San Diego sector, the study noted that as many as 6,000 aliens attempted to enter the United States illegally every night along the first 7-1/2 miles of border beginning at the Pacific Ocean. One of the reasons given in the study for this situation was that most of the border fencing in the San Diego sector and other urban areas was “poorly maintained” and “totally ineffective” (see fig. 3). However, as discussed on page 15, INS recently completed a new fence in the San Diego sector and plans additional fencing in other sectors. Border Patrol apprehensions along the southwest border declined between 1986 and 1989 but, although still below the 1986 level, apprehensions have gradually risen since then (see fig. 4). Figure 5 illustrates the prominence of the San Diego and El Paso sectors as border-crossing locations. In fiscal year 1993, these two sectors accounted for two-thirds of the 1.2 million southwest border apprehensions. Although the southwest border is approximately 1,600 miles long, much of it is difficult to cross by foot or vehicle due to rugged terrain, desert, or natural barriers such as some portions of the Rio Grande River. Our analysis of INS data showed that in fiscal year 1992 over half of all southwest border apprehensions occurred along only 18 of the 1,600 border miles—13 miles along the border between San Diego and Tijuana, Mexico, and 5 miles along the border between El Paso and Ciudad Juarez, Mexico. However, as we discussed on pages 23 to 25, recent border control initiatives in San Diego and El Paso appear to have rerouted some illegal immigrants to other southwest border areas. Unless border control efforts become more effective, illegal immigration is expected to increase. In September 1993, we reported that the flow of illegal aliens across the southwest border is expected to increase during the next decade because Mexico’s economy is unlikely to absorb all of the new job seekers that are expected to enter the labor force. The Border Patrol’s traditional tactic of discouraging illegal entry has been to apprehend aliens once they have entered the United States. According to the Sandia study’s authors, this tactic was inefficient and diminished the Border Patrol’s ability to control the border. In addition, the authors said the only good border control strategy is one that prevents people from crossing the border. The study concluded that the way to prevent illegal entry is to impose “effective barriers on the free flow of traffic.” The study noted that where it is not possible or practical to keep drugs and illegal aliens from entering the United States, they should be stopped at the earliest opportunity. In addition, the Sandia study concluded that “control of the illegal alien and drug traffic can be gained” and recommended that the Border Patrol change its tactics from apprehending illegal aliens after they have entered the United States to preventing illegal entry into the United States. A goal of a “prevention” strategy would be to significantly increase the difficulty of crossing the border illegally. The Sandia study concluded that single barriers, which had been used thus far, had not proven effective in preventing either drugs or illegal aliens from entering the country.