When he was Sec. of State under Hoover; there he got no where; Hoover - US would not go to war over China.
In 1933 Stimson had a meeting with FDR and discusses his "Stimson Doctrine" - nonrecognition of Japan, economic pressure, ...
When Stimson joins the FDR Cabinet as the Sec. of War, the "War Cabinet" start to move in the direction to probe Japanese ...
Your turn ... suggest expanding to role of other beyond US ...
Honestly, you’ve stumped me on that one, but it must have something to do with the British Empire... maybe?