Marine Expeditionary Unit, (MEU, pronounced Myuu), formerly called Marine Amphibious Unit (MAU), is the smallest Marine air-ground task force (MAGTF) in the United States Fleet Marine Force. Each MEU is an expeditionary quick reaction force, deployed and ready for immediate response to any crisis.
A Marine Expeditionary Unit is normally built around the building blocks of a MAGTF: a reinforced Marine infantry battalion is the ground combat element, the aviation combat element is a composite helicopter squadron, a battalion-sized logistics combat element, and a command element. Troop strength is about 2,200 and usually commanded by a colonel, and is deployed from an amphibious assault ship. Currently a Marine expeditionary unit embarks Marines and equipment onto the amphibious warfare ships of an Expeditionary Strike Group which also includes escort ships and submarines to protect them from air, surface, and submarine threats, for further protection and strong air support this is often along with one or more carrier battle groups.