In August 1943, Hasbrouck was assigned as deputy chief of staff for Twelfth United States Army Group, the headquarters that controlled most U.S. forces in Europe. In September 1944, he took command of Combat Command B, 7th Armored Division, which he led during combat in France following the Operation Overlord invasion. In November 1944, Hasbrouck was assigned to command the 7th Armored Division, which played a key role in stopping the German attack during the late 1944 Battle of the Bulge, and the March 1945 Battle of Remagen, which facilitated Allied access into Germany. He was promoted to major general in January 1945.