USCG has a broad and important role in homeland security, law enforcement, search and rescue, marine environmental pollution response, and the maintenance of river, Intracoastal and offshore aids to navigation (ATON). It also lays claim to being the United States' oldest continuous seagoing service. The United States Coast Guard has about 40,150 men and women on active duty.
The United States Coast Guard (USCG) is a part of the military of the United States combining aspects of a maritime law enforcement agency, an armed force, and a federal body. The Coast Guard has eleven statutory missions: Migrant Interdiction, Defense Readiness, Drug Interdiction, Ports, Waterways and Coastal Security, Other Law Enforcement, Search and Rescue, Aids to Navigation, Marine Safety, Living Marine Resources, Marine Environmental Protection, and Ice Operations.
The USCG has command responsibilities for the U. S. Maritime Defense Zone, countering potential threats to American coasts, ports, and inland waterways through numerous port-security, harbor-defense, and coastal-warfare operations and exercises.