The European Theater of Operations, United States Army (ETOUSA) was a theater of Operations responsible for directing United States Army operations throughout the European theatre of World War II, from 1942 to 1945. It commanded Army Ground Forces (AGF), United States Army Air Forces (USAAF), and Army Service Forces (ASF) operations north of Italy and the Mediterranean coast. It was bordered to the south by the North African Theater of Operations, United States Army (NATOUSA), which later became the Mediterranean Theater of Operations, United States Army (MTOUSA).

The United States Army Air Forces was the major land-based aerial warfare service component of the United States Army and de facto aerial warfare service branch of the United States during and immediately after World War II (1941–1947). It was created on 20 June 1941 as successor to the previous United States Army Air Corps and is the direct predecessor of the United States Air Force, today one of the six armed forces of the United States. The AAF was a component of the United States Army, which on 2 March 1942 was divided functionally by executive order into three autonomous forces: the Army Ground Forces, the United States Army Services of Supply, and the Army Air Forces. Each of these forces had a commanding general who reported directly to the Army Chief of Staff.