An amphibious readiness group (ARG) of the United States Navy consists of a naval element—a group of warships known as an amphibious task force (ATF)—and a landing force (LF) of U.S. Marines (and occasionally U.S. Army soldiers), in total about 5,000 people. Together, these elements and supporting units are trained, organized, and equipped to perform amphibious operations.
A typical U.S. Amphibious Readiness Group consists of:
The resulting forces may range from a single Amphibious Ready Group/Marine Expeditionary Unit (Special Operations Capable) [ARG/MEU (SOC)], to a larger organization capable of employing a Marine Expeditionary Brigade (MEB) or even a Marine Expeditionary Force (MEF).
Amphibious forces must be capable of performing missions ranging from humanitarian assistance and disaster relief to major theater war (MTW). Additionally, they can be configured and deployed to operate at various levels of conflict and in multiple theaters simultaneously. They can provide a presence that may preclude adventurous actions by a potential belligerent.
Because they are sea-based and because the decision to position and engage amphibious forces will always be easily reversible, amphibious forces greatly expand the repertoire of available response options. Among other national resources, they are particularly well placed to provide a demonstration of the United States's commitment and resolve to friends and allies as well as adversaries.
Normally two to three ARGs are forward deployed: one in the Mediterranean Sea/Persian Gulf–Indian Ocean area, and one or two in the western Pacific Ocean area. The other ships of the ARG are either working up to deploy, in transit, or in overhaul. One ARG/MEU, known as Task Force 76/Expeditionary Strike Group 7, is forward based in Sasebo and Okinawa, Japan.