Headquarters, Supreme Allied Commander Transformation (HQ SACT) is the only NATO command in North America and the only permanent NATO headquarters outside of Europe.

During the 2002 Prague Summit, NATO’s military command structure was reorganised with a focus on becoming leaner and more efficient.  One Strategic Command would be focused on NATO’s operations - Allied Command Operations and the other would be focused on transforming NATO - Allied Command Transformation (ACT).

ACT is NATO’s leading agent for change, driving, facilitating, and advocating continuous improvement of Alliance capabilities to maintain and enhance the military relevance and effectiveness of the Alliance.

ACT focuses on areas such as training and education, concept development, comprehensive approach, experimentation, and research and technology and using NATO's ongoing operations and work with the NATO Response Force (NRF) to improve the military effectiveness of the Alliance.

Reflecting NATO as a whole, ACT has a worldwide presence. As well as being co-located with United States Joint Forces Command in Norfolk, Virginia, there is an ACT command element located in Belgium.

Additional command elements assist in ACT's transformation efforts include the Joint Warfare Centre in Stavanger, Norway; the Joint Force Training Centre in Bydgoszcz, Poland; and the Joint Analysis and Lessons Learned Centre in Monsanto, Portugal.