On March 16, 2011, Rear Adm. Paul Zukunft, the Coast Guard’s assistant commandant for marine safety, security, and stewardship, testified before the House Appropriations Subcommittee on Homeland Security about the Coast Guard’s role in enforcing the Southwest border.

While many Americans are aware of the patrol and interdiction work the Coast Guard performs along the U.S./Mexican maritime border, Zukunft described a complex, “three-layered” role. Coast Guard work near the maritime border is primarily defensive, performed in reaction to incursions. In order to address an increasingly sophisticated and complex series of threats, however, the Coast Guard has adapted and formed partnerships aimed at preventing such incursions from being attempted.

These adaptations are most evident in the way the Coast Guard fights the flow of illegal drugs from South and Central American points of origin: With numerous federal and international partners (the U.S. maintains 37 bilateral counter-drug agreements with nations in source areas and the Transit Zone, or Eastern Pacific approaches to U.S. waters), the Coast Guard confronts threats well beyond U.S. waters. Interdictions are performed by Coast Guard Law Enforcement Detachments (LEDETs), often embarked on U.S. Navy and allied naval vessels.

In recent years, Coast Guard LEDETs have become increasingly adept at countering the use of self-propelled semi-submersible (SPSS) vessels, one of the drug cartels’ latest gambits. SPSSs are hard to detect and easily scuttled before they can be boarded, but LEDETs have become more proficient at conducting surprise boardings and seizing evidence that can be used in court. In calendar year 2010 alone, the Coast Guard and its Interagency Task Force partners conducted 106 major counter-narcotics cases, seizing more than 200,000 pounds of cocaine and 36,000 pounds of marijuana bound for the United States.

The Coast Guard is the nation’s primary representative in the second layer described by Zukunft: the North American Maritime Security Initiative (NAMSI), a close working relationship with Mexican authorities, launched in 2008, that has allowed for joint operations and information sharing to prevent incursions from Mexican coastal waters.

The third and final layer of border protection offered by the Coast Guard consists of the U.S. Customs waters just north of the U.S. maritime border with Mexico, an area where the Coast Guard works closely with Customs and Border Protection (CBP), Immigration and Customs Enforcement (ICE), and state and local partners to detect and interdict maritime incursions.

Attempts by illegal migrants to cross the Southwest border by sea have become increasingly common over the past two years, and mark a dramatic change in tactics: traditionally, migrants have tried to blend in with recreational boating activity, hugging the coastline and dropping off passengers just across the border or near San Diego transportation corridors. Many recent attempts, however, have gone far beyond the border, some as far as the Los Angeles area. These migrants often venture far off the coast, near California’s Channel Islands, to avoid detection.

These increasingly dangerous voyages are often attempted in small boats powered by single outboard motors, and the Coast Guard’s primary concern in such cases is avoiding the loss of life. In late fall of 2010, an MH-60 Jayhawk helicopter crew and the CGC Sea Otter rescued 17 suspected illegal migrants from a disabled vessel about 23 miles east of San Clemente Island. In January of 2010, two suspected migrants drowned when their boat overturned in the surf at Torrey Pines State Beach; in July of 2011, the Coast Guard cutter Blackfin, along with National Park Service personnel, rescued 15 suspected migrants who had become stranded on Santa Cruz Island – well north of Los Angeles, off the coast of Santa Barbara.

Increased migrant activity along maritime routes has caused the Coast Guard and its partners to step up enforcement activity and try to intercept these boats before they get into trouble.

Preventing trouble was a powerful theme in Zukunft’s address. “Our unambiguous goal,” he said, “is to meet threats far from the U.S. border.” As a law enforcement agency working with partners far from U.S. shores, Zukunft pointed out, the Coast Guard had become a valuable – and unique – member of the U.S. intelligence community, valued not only for its role in enforcing the border, but also for helping to describe what goes on there. “Our intelligence personnel have access to a myriad of national security information that, when combined with law enforcement information, results in a higher level of accuracy and a greater reach for support to intelligence-driven operations,” Zukunft said to Congress. “No other federal agency has this level of cross-cutting access.”