He attended the Army War College, graduating in 1921, and remaining for a year as an instructor, where he taught such classes as the "Art of Command". He paid a four-month visit to Germany in 1922 as part of the War College's Historical Section, during which he examined documents related to World War I in the German War Archives. These informed his lectures on the war, and he argued that much of the German Army's effectiveness was attributable to its system of decentralized command.