In recent years some have asked why greater use cannot be made of the armed forces in turning back the flood of illicit narcotics threatening to swamp this nation. In fact, from 1989 to 1997 members of the United States Atlantic Command played a significant part in the government's effort to stem the flow of illegal drugs across the Caribbean and into this country. Acting to support civilian law-enforcement authorities, they have provided exceptional tracking, communications, and logistic assistance for the politically mandated effort that ensued.
American law limits the armed forces in law enforcement.
If, as the result of emergency or disaster, a situation deteriorates to the point that federal military forces are required to maintain order, a presidential declaration is required before troops can be used. The act, which applies on its face to only the Army and the Air Force, has been extended by administrative action to include the Navy and the Marine Corps. The only armed force exempted from Posse Comitatus is the Coast Guard. Then a part of the Treasury Department, it served well in Prohibition enforcement between 1920 and 1933. Today, as part of the Transportation Department, it has both military responsibilities and maritime law-enforcement duties on the high seas.