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. SPOBS 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. On 5 May 1942, Maj. Gen.
John C. H. Lee became Commanding General, Services of Supply, U.S. Army Forces British Isles, and later deputy theater commander, ETOUSA. On 8 June 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. The 133rd Infantry Regiment of the
34th Infantry Division was the first
United States Army unit sent to Europe in World War II. The first battalion arrived in
Belfast in late January 1942, followed by the rest of the regiment in February. These units were designated as U.S. Army Northern Ireland Forces, later incorporated within the European Theater of Operations. The 133rd and 168th Infantry Regiments trained in the peat bogs, and performed border guard patrols between British Northern Ireland and
neutral Ireland. The remaining unit of the division, the 135th Infantry Regiment, arrived in May 1942. From February 1944 the operational command was the
Supreme Headquarters Allied Expeditionary Force (SHAEF) which as an Allied command also had operational control of British, American, and all other allied land forces and tactical airforces in the European
theatre. Until SHAEF was operational ETOUSA liaised closely with the British in the planning and organising of
Operation Overlord. U.S. General
Dwight D. Eisenhower had multiple command appointments; he replaced Chaney in late June 1942, but in November he also commanded the Allied forces in
Operation Torch through AFHQ. Operation Torch—the invasion of French North Africa—involving the
9th,
3rd Infantry and the
2nd Armored Divisions, initiated on 8 November 1942, was the first ground combat operations for the United States in the European theater of World War II. Eisenhower then relinquished command of ETOUSA to Lt. Gen.
Frank Maxwell Andrews in February 1943, who was killed in an air crash in May. He was replaced by Lt. Gen.
Jacob L. Devers, former Chief of the Armored Force. In December 1943 it was announced that Eisenhower would be Supreme Allied Commander in Europe. In January 1944 he resumed command of ETOUSA and the following month was officially designated as the Supreme Commander of the Allied Expeditionary Forces. (Note that Supreme Headquarters of the Allied Expeditionary Forces (SHAEF) was the headquarters of the Commander of the Allied Expeditionary Forces, whereas the AFHQ was the headquarters of only the Allied forces.) He served in a dual role until the end of hostilities in Europe in May 1945. From February 1944, SHAEF was the operational command and ETOUSA administrative command. Some units were transferred between operational commands and administrative commands at different times. For example, the
American 6th Army Group, which was set up under the
Mediterranean Theater of Operations, commanded by Devers, to oversee
Operation Dragoon, the invasion of
Southern France between
Toulon and
Cannes, was passed to SHAEF (and into ETO) a month after the invasion which took place on 15 August 1944. By the end of 1944, Eisenhower, through SHAEF, commanded three powerful Allied army groups. In the north
British 21st Army Group commanded by Field Marshal
Bernard Montgomery (
"Monty"), in the middle the
American 12th Army Group commanded by General
Omar N. Bradley, and in the South the
American 6th Army Group commanded by Devers. The British 21st Army Group and French elements of the 6th Army Group were not part of ETOUSA, but by that stage of the war most of the operational forces under the command of SHAEF were American. The ETOUSA planning staff in London was usually referred to by its
Army Post Office number, "APO 887". After the war in Europe ended on May 8, 1945, ETOUSA became briefly U.S. Armed Forces Europe, then U.S. Forces, European Theater (USFET), and then, eventually,
United States Army Europe.
Albert Coady Wedemeyer was chief author of the
Victory Program, published three months before the U.S. entered the war in 1941, which advocated the defeat of the German armies on the European continent. When the U.S. entered the war after the Japanese bombed Pearl Harbor on 7 December 1941 and the U.S. was at war with both Japan and Germany, a "
Europe first" a modified version of his plan was adopted by U.S. President
Franklin D. Roosevelt and British Prime Minister
Winston Churchill. Under the German first policy, the plan was expanded to include the
blueprint for the
Normandy landings. ==Successor organizations==