Now the Drug Enforcement Administration, Coast Guard and other federal agencies might have to be more careful about their pursuit of these drug-laden vessels, making sure interdictions occur beyond the 12-mile territorial boundary of a foreign country.

“If this decision stands, it’s not going to be a deadly blow to the war on drugs,” said Miami attorney David Weinstein, who once ran the narcotics section of the U.S. attorney’s office in South Florida. “But it is going to increase the level and depth of communications between the United States and foreign countries as they battle drug-trafficking together.”

While the impact of the appeals court’s decision remains to be seen, federal prosecutors in Miami have stepped up efforts to crack down on drug smuggling in the Caribbean.

In August 2011, U.S. Attorney Wifredo Ferrer launched an initiative to target narcotics shipments from Colombia through the Caribbean basin, as he sounded a warning that authorities had detected an uptick in smuggling activity.

They said the U.S. government’s anti-drug efforts on the Mexican border caused a “balloon effect” that spurred more narcotics trafficking through the Caribbean as an alternative route.

Over the past year, the U.S. attorney’s office said it has brought cocaine-importation and other drug charges against more than 200 defendants who have used the Caribbean basin to transport drugs to the United States.

Assistant U.S. Attorney George Karavetsos, who heads the narcotics section, said that total represented a sharp increase in prosecutions over each of the past three years.

To spotlight the Caribbean crackdown, both Karavetsos and Ferrer attended for the first time the Association of Caribbean Commissioners of Police meeting in the Bahamas last May.

“We are here because we recognize we share a common threat,” Ferrer said in his address, as he warned police officials about the balloon effect.