Prior to building a new NATO command structure the Allies had already established as part of the new force structure a number of High Readiness Forces (Land) headquarters modelled on the Allied Command Europe Rapid Reaction Corps (ARRC) and supplemented by other headquarters at lower readiness. These deployable headquarters can command and control forces from the size of a brigade numbering thousands of troops up to a corps of tens of thousands.

The majority of deployable forces are held at high readiness to support both collective defence Alliance-wide and crisis response operations wherever they might occur. The multinational deployable forces are commanded by air, land, maritime and special operations forces headquarters provided by a framework nation or number of nations working in concert. Force packages are built around these headquarters dependent upon the task. These deployable headquarters can command and control forces from the size of a brigade numbering thousands of troops up to a corps of tens of thousands, aircraft to deliver hundreds of sorties per day, or maritime task forces of varying size dependent upon the task.

In addition to HQ ARRC, the Supreme Allied Commander Europe (SACEUR) has eight other Graduated Readiness Forces (Land) Headquarters under Supreme Headquarters Allied Powers Europe (SHAPE) operational command. Several of these headquarters have taken turns in the past commanding the International Security Assistance Force (ISAF) in Afghanistan and also take turns providing the 12-month rotating Land Component Command (LCC) or Joint Task Force (JTF) headquarters of the NATO Response Force (NRF)

There are five High Readiness Forces (Maritime) headquarters that can command and control assigned forces up to the level of a NATO naval task force made up of dozens of warships. Each headquarters provides the Maritime Component Command (MCC) for the NRF on a rotational basis. Additionally there are three deployable High Readiness Forces (Air) headquarters provided by the United Kingdom, France and Germany, which also provide the Air Component Command (ACC) for the NRF on a rotational basis.