Supreme Headquarters Allied Powers Europe Supreme Headquarters Allied Powers Europe Supreme Headquarters Allied Powers Europe (SHAPE) is the headquarters of the North Atlantic Treaty Organization's Allied Command Operations (ACO). SHAPE is located at Casteau, north of the Belgian city of Mons. The commander of ACO and SHAPE is Supreme Allied Commander Europe (SACEUR), a U.S. four-star general officer or flag officer who also serves as Commander, U.S. European Command. Since 1967 it has been located at Casteau, north of the Belgian city of Mons, but it had previously been located, from 1953, at Rocquencourt, next to Versailles, France. From 1951 to 2003, SHAPE was the
Western Union (alliance) transferred to the newly established North Atlantic Treaty Organisation (NATO), providing the nucleus of NATO's command structure at the Supreme Headquarters Allied Powers Europe (SHAPE). As a consequence of the failure of the European Defence Community in 1954, the London and Paris Conferences led to the Modified Treaty of Brussels (MTB) through which the Western Union was transformed into the Western European Union (WEU) and was joined by Italy and West Germany. As the WEU's functions were transferred to the European Union's (EU) European Security and Defence Policy (ESDP) at the turn of the 21st century, the Western Union is