European Theater of Operations, United States Army

European Theater of Operations, United States Army (ETOUSA)
Active	1942–45
Country	United States
Branch	United States Army
Type	Theater Army
Role	Headquarters
Part of	War Department Allied Expeditionary Force
Nickname(s)	"ETOUSA"
Anniversaries	V-E Day (8 May)
Campaigns	World War II
Commanders
Notable commanders	Dwight D. Eisenhower Frank Andrews Jacob Devers

The European Theater of Operations, United States Army (ETOUSA) was a United States Army formation which directed US Army operations in parts of Europe from 1942 to 1945. It referred to Army Ground Forces, United States Army Air Forces, and Army Service Forces operations north of Italy and the Mediterranean coast, in the European Theater of World War II. It was bordered to the south by the North African Theater of Operations, US Army (NATOUSA), which later became the Mediterranean Theater of Operations (MTOUSA).

The term theater of operations was defined in the US Army field manuals as the land and sea areas to be invaded or defended, including areas necessary for administrative activities incident to the military operations. In accordance with the experience of World War I, it was usually conceived of as a large land mass over which continuous operations would take place and was divided into two chief areas-the combat zone, or the area of active fighting, and the Communications Zone, or area required for administration of the theater. As the armies advanced, both these zones and the areas into which they were divided would shift forward to new geographic areas of control.

British–American military staffs agreed during their meetings in Washington in January–March 1941 (the ABC-1 Conversations) to exchange military missions to facilitate planning for the eventuality of American entry in the war. Major General James E. Chaney, an Army Air Corps officer, arrived in the United Kingdom on 18 May 1941, and on the following day, Headquarters, Special Observer Group (SPOBS), was established in London. SBOPS also had the role of studying British use of Lend Lease supplies. His formal title was the Special Army Observer in the United Kingdom and head of SPOBS. After the United States entered the war, SPOBS was succeeded by United States Army Forces in the British Isles (USAFBI), actually SPOBS under a new name. At the time of the ARCADIA Conference, December 1941 – January 1942, the decision was made to place the MAGNET forces (U.S. Forces for Northern Ireland) under the command of Maj. Gen. E.L. Daley, and make him in turn responsible to General Chaney, designated as CG, USAFBI. Lt. Gen. John C. H. Lee became Chief, Services of Supply, U.S. Army Forces British Isles, and later deputy theater commander, ETOUSA. On June 8, 1942, the United States Department of War officially established ETOUSA in its place. Its mission was to conduct planning for the eventual retaking of Europe and to exercise administrative and operational control over U.S. forces.

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