"Who conducted American diplomacy before and during the war? The answer is: most definitely not Cordell Hull, our longest-serving Secretary of State (1933-1945). Mr. Hull is remembered best for two things: setting policy on trade tariffs and getting out of the way when the White House wanted to make policy. Harry Hopkins, Sumner Wells and other special agents were FDR’s real policy-makers at that time. As Hull himself put it, “If the President wishes to speak to me, all he has to do is pick up that telephone of his, and I’ll come running. But it’s not for me to bother the president.” The State Department was very much out of the loop for much of the diplomacy of World War II. For example, at the Tehran Conference, which decided much of the structure of postwar Germany, no State Department representative was present, only military officers from the Joint Chiefs of Staff. This trend has since continued, with growing influence of the military in foreign policy decision-making."
Jack Zetkulic Senior Foreign Service Officer Excerpted from U.S Diplomatic History in Brief – a Foreign Service Perspective (From Historical Sketches: US Diplomacy)