NATO Centre of Excellence

Allied Command Transformation
Allied Command Transformation Emblem
Active	Since 19 June 2003
Country	NATO / OTAN
Headquarters	Norfolk, Virginia
Commanders
Current commander	Général Denis Mercier, French Air Force

Allied Command Transformation (ACT; French: Le Commandement allié Transformation) is a NATO military command, which was formed in 2003 after North Atlantic Treaty Organisation restructuring.

It was intended to lead military transformation of alliance forces and capabilities, using new concepts such as the NATO Response Force and new doctrines in order to improve the alliance's military effectiveness. Since France rejoined the NATO Military Command Structure in mid-2009, a significant change took place where the Supreme Allied Commander Transformation (SACT) became a French officer. The first French Officer to serve as SACT was French Air Force General, Stephane Abrial (2009–2012).

Allied Command Transformation was preceded by Allied Command Atlantic (ACLANT) established in 1952 under the overall command of Supreme Allied Commander Atlantic (SACLANT), with its headquarters at Norfolk, Virginia. ACLANT's purpose was to guard the Sea lines of communication between North America and Europe in order to reinforce the European countries of NATO with U.S. troops and supplies in the event of a Soviet/Warsaw Pact invasion of Western Europe. Following the end of the Cold War, the Command was reduced, with many of its subordinate headquarters spread across the Atlantic area losing their NATO status and funding. However, the basic structure remained in place until the Prague Summit in the Czech Republic in 2002. This led to ACLANT being decommissioned effective 19 June 2003, and a new Allied Command Transformation being established as its successor.

Admiral Edmund P. Giambastiani Jr. US Navy became the last SACLANT on 2 October 2002. He served as ACLANT commander until 19 Jun 2003. He then served as Supreme Allied Commander, Transformation, until 1 Aug 2005. Admiral Sir Mark Stanhope RN, the Deputy Supreme Allied Commander, then served as Acting Supreme Allied Commander until the arrival of General Lance L. Smith USAF in November 2005.