After the
First World War, Gooch became an influential historian of Europe of the period and was critical of British policy. He was active in the
Union of Democratic Control. For about ten years from the mid-1920s onwards, he was involved, with
Harold Temperley, in the publication of the official British diplomatic history. The selection of Gooch for the project selection was made over the reservations of
James Wycliffe Headlam-Morley and of Temperley himself, who believed that Gooch was too committed to a pro-German position and too critical of Sir
Edward Grey. Gooch has been noted as a significant
revisionist historian of the Europe of the early 20th century, in particular in relation to the causes of the First World War. He has been described as one of the "early revisionists", alongside
Harry Elmer Barnes and
Sidney Bradshaw Fay. ==Awards and honours==