America's Greatest Military Foe 3: Admiral Isoroku Yamamoto?

By the time we reach World War II, naval operations were becoming even more important to warfare. In 1890, Mahan wrote one of the most important treatises on the subject. World War I demonstrated the power of the U-boat, and by World War II, ruling the waves was critical to maintaining operations, especially for island powers like Japan and Britain (though I'm sure Britain would not like me to refer to it that way). While America had Nimitz, Japan's naval forces rested in the eminently capable hands of Isoroku Yamamoto.