If Article 5 of the NATO Treaty were invoked, the Allied Rapid Reaction Corps, with 1,600 troops from 23 nations, could be deployed to lead up to 160,000 ground troops. Annual exercise ARRCADE FUSION tests their readiness. The Allied Rapid Reaction Corps, or ARRC, is the high-readiness Land Component Command or Corps HQ for NATO, an operationally effective HQ capable of deploying worldwide on short notice.
The ARRC was created on 2 October 1992 in Bielefeld based on the former British I Corps (or I (BR) Corps). It was originally created as the rapid reaction corps sized land force of the Reaction Forces Concept that emerged after the end of the Cold War, with a mission to redeploy and reinforce within Allied Command Europe (ACE) and to conduct Petersberg missions out of NATO territory. The first commander, appointed in 1992 was General Sir Jeremy Mackenzie.
From 1994 the ARRC was based in the Rheindahlen Military Complex, Germany. It commanded the Land Forces of NATO’s first ever deployment as part of the IFOR operation in Bosnia in 1995/6 and was again deployed as the headquarters commanding Land Forces during the Kosovo War in 1999.
Since 2002 however the HQ has been re-roled (with five other corps HQs of other NATO nations) as a High Readiness Force (Land) HQ (HRF(L)) with a broader mission. The formation HQ is under Operational Command of Supreme Allied Commander, Europe (SACEUR). The ARRC has a national Force Pool of Combat, Combat Support and Combat Service Support units with which to train and execute its mission. However, in reality COMARRC commands no forces until he receives an Activation Order from SACEUR. On receipt of ACTORD, forces from troop contributing nations, generated through the NATO Force Generation process are passed into his Operational Command for the duration of the operational deployment.
Although the corps is commanded by a British Army lieutenant-general, the corps is no longer a purely British formation. The UK is the ‘framework nation’ and provides about 80% of the funding and 60% of the staff for the HQ. The remaining 40% of the staff are made up of a further 14 Partner Nations.
The ARRC has previously deployed to Afghanistan, Bosnia and Herzegovina, Iraq and Kosovo.