propinquity = power

Readers here know that I get really excited about deeply researched books that change the common view on historical events. I've just read another, Phillips Payson O'Brien's new biography of Admiral William Leahy, The Second Most Powerful Man in the World.

Until I read O'Brien's book, I had long believed that General George Marshall was the military hero of World War II and the most influential officer advising Franklin Roosevelt. I also thought that the most influential civilian around FDR was Harry Hopkins, who even lived in the White House for over three years [1940-43].

What O'Brien documents is that Leahy had a longstanding relationship with FDR and spent long hours and numerous personal meetings with the president. He assiduously avoided publicity, however, and frequently said little in group meetings.  Once he became the Chairman of the Joint Chiefs of Staff and de facto chief of staff for all White House matters in 1942, he became the closest confidante and advisor to the president. While Hopkins was also influential and given several key assignments to fly to foreign capitals, he was frequently ill and hospitalized.  Leahy traveled almost constantly with FDR, to Hyde Park and elsewhere, and was always close at hand.

I'm willing to believe that propinquity is a good measure of power, and Leahy had that. O'Brien also demonstrates [there's even a chart on p. 281] that on key disputes over wartime strategy, FDR always sided with Leahy and against Marshall: the North Africa invasion; priority for air and sea construction programs; limiting the army's size in favor of war production; delaying D-Day until 1944.  O'Brien argues that Leahy stealthily worked to send assets to the Pacific despite the declared "Germany First" strategy.

Using the name metric, O'Brien persuasively argues that Cordell Hull and even Henry Stimson were bit players in the wartime strategy. 

From mid-1943 until FDR's death and the German surrender, Leahy was often "acting president" during the many low points in Roosevelt's declining health.

I see that there are several recent books on WWII leaders, but this is the best for explaining how the inner circle worked.