Allied Command Operations (ACO)

  • Last updated: 03 Oct. 2018 11:37

Allied Command Operations (ACO) is responsible for the planning and execution of all Alliance operations. It consists of a small number of permanently established headquarters, each with a specific role. Supreme Allied Commander Europe – or SACEUR – assumes the overall command of operations at the strategic level and exercises his responsibilities from the headquarters in Mons, Belgium: Supreme Headquarters Allied Powers Europe, more commonly known as SHAPE.


  • ACO, with its headquarters at SHAPE near Mons, Belgium, is responsible for the planning and execution of all NATO military operations and is headed by SACEUR.
  • It has the ability to operate at three overlapping levels: strategic, operational and tactical.
  • The command’s overall aim is to contribute to Allied defence and security by maintaining the integrity of Alliance territory, safeguarding freedom of the seas and economic lifelines, and to preserve or restore the security of its members.
  • Allied Command Operations is one of two Strategic Commands at the head of NATO’s military command structure. The other is Allied Command Transformation, which is responsible for ensuring NATO’s military structure and capabilities remain relevant, capable and credible in a rapidly changing world.
  • ACO consists of a number of permanently established headquarters operating at the strategic, operational and tactical levels; they are augmented by national forces assigned to NATO for specific standing and/or crisis roles and tasks.
  • The structure of Allied Command Operations

    ACO is one of two Strategic Commands within NATO's military command structure; the other is Allied Command Transformation (ACT), which – as its name indicates – leads the transformation of NATO's military structure, forces, capabilities and doctrine. Together with their subordinate organisations, they form what is called the NATO Command Structure (NCS), whose function is first and foremost to be able to respond to security threats to the Alliance and, should deterrence fail, provide a capable and effective military response to an armed attack against the territory of any of the European1 Allies.

    Ultimately, the NCS plays an essential role in preserving cohesion and solidarity within the Alliance, maintaining and strengthening the vital transatlantic link and promoting the principle of equitable sharing among Allies of the roles, risks and responsibilities, as well as the benefits of collective defence.

    ACO is a three-tier command with headquarters and supporting elements at the strategic, operational and tactical levels. It exercises command and control of static and deployable headquarters, as well as joint and combined forces across the full range of the Alliance's military operations, missions, operations and tasks. Joint forces are forces from two or more military services (for instance, land, maritime or air) working under a single command; combined forces are forces from different countries working under a single command.

    SHAPE, at the strategic level, is at the head of six operational commands, two of which are supported by tactical (or component) level entities.

    At the 2018 Brussels Summit, Allies agreed to strengthen the military backbone of the Alliance. They decided to establish a Cyberspace Operations Centre in Belgium to provide situational awareness and coordination of NATO operational activity within cyberspace; a Joint Force Command Norfolk headquarters in the United States to focus on protecting the transatlantic lines of communication; and a Joint Support and Enabling Command in Germany to ensure freedom of operation and sustainment in the rear area in support of the rapid movement of troops and equipment into, across and from Europe. These new entities are gradually being put into place.

    Strategic-level command: SHAPE

    SHAPE is a strategic headquarters. Its role is to prepare, plan, conduct and execute NATO military operations, missions and tasks in order to achieve the strategic objectives of the Alliance. As such, it contributes to the deterrence of aggression and the preservation of peace, security and the territorial integrity of Alliance.

    ACO is headed by SACEUR, who exercises his responsibilities from SHAPE. Traditionally, he is a United States Flag or General officer. SACEUR is dual-hatted as he is also the commander of the US European Command, which shares many of the same geographical responsibilities as ACO. SACEUR is responsible to the Military Committee, which is the senior military authority in NATO under the overall political authority of the North Atlantic Council (NAC) and the Nuclear Planning Group (NPG). The Military Committee is the primary source of military advice to the NAC and NPG.

    Operational-level commands: Brunssum and Naples

    The operational level consists of two standing Joint Force Commands (JFCs): one in Brunssum, the Netherlands, and one in Naples, Italy. Both stand ready to plan, conduct and sustain NATO operations of differing size and scope across the full spectrum of military response. Their role is to manage major joint operations either from their static location in Brunssum or Naples, or from a deployed headquarters when operating directly in a theatre of operation. In the latter case, the deployed headquarters is referred to as a Joint Task Force HQ or JTFHQ and is able to operate for a period of up to one year.

    When a JFC is not deployed, it supports ACO in dealing with headquarters which are deployed on operations, missions and tasks, for instance, with the training and preparation for future rotations. When deployed, a JFC is only charged to command one operation at a time; if there are some elements of this JFC which have not deployed, they continue to support other operations and missions.

    The two commands at this level are also responsible for engaging with key partners and regional organisations in order to support NATO HQ tasks and responsibilities, as directed by SACEUR. Additionally, they facilitate cooperation with partners participating in NATO operations and help to prepare partner countries, which so wish, for NATO membership.

    Tactical-level commands: Izmir (Land), Northwood (Maritime) and Ramstein (Air)

    The tactical (or component) level consists of what are called Single Service Commands (SSCs): land, maritime and air commands. These service-specific commands provide expertise and support to the Joint Force Commands. They report directly to SHAPE and come under the command of SACEUR.

    • Land Command, Headquarters Allied Land Command (HQ LANDCOM), Izmir, Turkey: this command's role is to provide a deployable land command and control capability in support of a Joint Force Command running an operation larger than a major joint operation. It can also provide the core land capability for a joint operation (major or not) or a deployable command and control capability for a land operation. Izmir is also the principal land advisor for the Alliance and contributes to development and transformation, engagement and outreach within its area of expertise.
    • Maritime Command, Headquarters Allied Maritime Command (HQ MARCOM), Northwood, the United Kingdom: this command's role is to provide command and control for the full spectrum of joint maritime operations and tasks. From its location in Northwood, it plans, conducts and supports joint maritime operations. It is also the Alliance's principal maritime advisor and contributes to development and transformation, engagement and outreach within its area of expertise. Northwood is able to command a small maritime joint operation or act as the maritime component in support of an operation larger than a major joint operation.
    • Air Command, Headquarters Allied Air Command (HQ AIRCOM), Ramstein, Germany: this command's role is to plan and direct the air component of Alliance operations and missions, and the execution of Alliance air and missile defence operations and missions. Ramstein is also the Alliance's principal air advisor and contributes to development and transformation, engagement and outreach within its area of expertise. Ramstein, with adequate support from within and outside the NATO Command Structure can provide command and control for a small joint air operation from its static location, i.e., from Ramstein or can act as Air Component Command to support an operation which is as big or bigger than a major joint operation. To reinforce its capability, Ramstein has additional air command and control elements available: two Combined Air Operations Centres (CAOC) and a Deployable Air Command and Control