The II Marine Expeditionary Force (II MEF) is a Marine Air-Ground Task Force consisting of ground, air and logistics forces capable of projecting offensive combat power ashore while sustaining itself in combat without external assistance for a period of 60 days.

II MEF units are available for and prepared to respond to contingency requirements worldwide.

[1] In addition to the option of being employed in its entirety as a MEF-sized unit, II MEF has the capability of forming task-organized Marine Air-Ground Task Forces (MAGTF) of lesser size such as a MEF (Forward), a brigade-sized MAGTF (Marine Expeditionary Brigade or "MEB") about one-third the size of a MEF or a Marine Expeditionary Unit (MEU), about one-third the size of a MEB.

At the same time, tactical aircraft of the MEB are flight ferried to an airfield in or near the area of operation.

The MEU consists of approximately 2,200 Marines and Sailors, is capable of rapid response in a variety of possible contingencies, and if the situation requires, can serve as the forward element of a larger MAGTF.