The US Marine Corps (USMC) is ready at a moment's notice to deploy a highly scalable force rapidly anywhere around the world.

The Marine Air-Ground Task Force (MAGTF) is a term used by the USMC to describe the principal organisation for all missions across the range of military operations.

MAGTFs are a balanced air-ground, combined arms task organisation of Marine Corps forces under a single commander that is structured to accomplish a specific mission.

Each MAGTF has four core elements: a command element that includes a headquarters unit that directs the other elements; a ground combat element comprising infantry supported by armor and artillery; an aviation combat element that includes all aircraft, both fixed wing and helicopters; and a logistics combat element that contains all of the support units for the MAGTF, such as communications, combat engineers, motor transport, medical, supply units, and certain specialised groups such as air delivery and landing support teams.

"MAGTFs have long provided the United States with a broad spectrum of response options when US and allied interests have been threatened and in non-combat situations which require instant response to crisis," according to the USMC website.

"Selective, timely and credible commitment of air-ground units have, on many occasions, helped bring stability to a region and sent signals worldwide that the United States is willing to defend its interests, and is able to do so with a significantly powerful force on extremely short notice."

Scalability

The size of each MAGTF depends on its mission, but its structure never varies. Each one can operate either alone or as part of a coalition.

The largest type of MAGTF is a Marine Expeditionary Force (MEF), which is made up of 46,000–90,000 marines.

The USMC has three of them -- I MEF, II MEF and III MEF -- to serve as its primary warfighting force for larger operations.

Commanded by a lieutenant general, each of the MEFs is capable of projecting power on land or at sea and is able to support itself in combat for up to 60 days.

Each one includes a full Marine Division, a Marine Aircraft Wing and a Marine Logistics Group.

Depending on the circumstance, the entire MEF could deploy, or it could deploy smaller MAGTFs.

Marine Expeditionary Brigades (MEBs), which are task organised for specific missions, represent the next size of MAGTF.

Scaled with 4,000–16,000 Marines and commanded by a brigadier general, the MEB includes a regimental-size ground combat element, an aircraft group and a combat logistics regiment.

Each MEB can support itself for 30 days.

The smallest MAGTF is the Marine Expeditionary Unit (MEU), which is forward deployed and often the first to arrive at a crisis.

Designed to be versatile and quick to respond, an MEU usually has 2,200 Marines and includes a battalion landing team, composite helicopter squadron and combat logistic battalion.

MEUs are commanded by a colonel and can support themselves for 15 days.