As Ambassador to Japan (1932–1941), he opposed American hardliners and recommended negotiation with Tokyo to avoid war until the Japanese attack on Pearl Harbor (December 7, 1941).

He became acting chief of the State Department's Division of Western European Affairs during the war (1917–1919) and was the secretary of the American peace commission in Paris (1919–1920).

He replaced Hampson Gary as the United States Ambassador to Switzerland after his appointment by President Warren Harding.

From April 16, 1924 to June 30, 1927, Grew served as the Under Secretary of State in Washington under President Calvin Coolidge and succeeded William Phillips.

[7] In 1924, the Rogers Act created a merit-based hiring process that enabled Clifton Reginald Wharton Sr. to later that year become the first Black member of the Foreign Service.

[8] Grew used his position to manipulate the oral part of the exam specifically to prevent further hiring of Black candidates.

In 1932, Grew was appointed by President Herbert Hoover[1] to succeed William Cameron Forbes as the Ambassador to Japan, where he took up his posting on June 6.

During his long tenure in Japan he became well known to the American public, making regular appearances in newspapers, newsreels and magazines, including an appearance on Time magazine's cover in 1934, and a long 1940 feature story in Life in which writer John Hersey, later famous for Hiroshima, called Grew “unquestionably the most important U.S. ambassador” and Tokyo the “most important embassy ever given a U.S. career diplomat.” [1] One major episode came on 12 December 1937.

The adjoining photograph showed them having tea together in 1937 after attending a goodwill event to commemorate the 25th anniversary Japanese gift of cherry blossom trees to the US in 1912.

[13] [14] The historian Jonathan Utley argues in Before Pearl Harbor that Grew took the position that Japan had legitimate economic and security interests in Greater East Asia and that he hoped that President Roosevelt and Secretary of State Hull would accommodate them by high-level negotiations.

[18] Grew served as ambassador until December 8, 1941, when the United States and Japan severed diplomatic relations during the Japanese bombing of Pearl Harbor.

On April 18, 1942, Grew watched US B-25 bombers carry out the Doolittle Raid, bombing Tokyo and other cities after taking off from aircraft carriers in the Pacific.

Assistant Secretary of War John J. McCloy drafted a proposed surrender demand for the Committee of Three, which was incorporated into Article 12 of the Potsdam Declaration.

President Harry S. Truman, who was influenced by Secretary of State James F. Byrnes during the trip via warship to Europe for the Potsdam Conference, changed the language of the demand for surrender.

Grew advocated a soft peace that would be acceptable to the Japanese people and would maintain an honorable status for the Emperor.

He successfully opposed treating the Emperor as a war criminal and thereby prepared the way for a speedy Japanese surrender and the friendly postwar relations during which Japan was closely supervised by American officials.

[22] By May 1945, the U.S. held a number of Soviet prisoners-of-war (POWs) who had been captured while serving voluntarily or involuntarily[23] in some capacity in the German Army, mostly as rear area personnel (ammunition bearers, cooks, drivers, sanitation orderlies, or guards).

In any case, in Stalin's eyes, they were dead men, as they had been captured alive, "contaminated" by contact with those in bourgeois Western nations, and found in service with the German Army.

Your description, both of the actual hunting and the people and surroundings, is really excellent;...In 1945, after Grew left the State Department, he wrote two volumes of professional memoirs, published in 1952.

Through her paternal grandfather, Alice was a great-granddaughter of famed American naval hero Oliver Hazard Perry.

Tora!, a historical drama about the 1941 Japanese attack on Pearl Harbor, the part of US Ambassador Joseph Grew was played by Meredith Weatherby.