The planning, execution and consequences of Operation Vengeance - the interception, shoot-down and death of Admiral Isoroku Yamamoto, Commander-in-Chief of the Imperial Japanese Navy and the architect of Japan's surprise attack upon the U.S. Fleet at Pearl Harbor - have generated a sizable literature. This Osprey title, the 53rd in its Raid Series, is a succinct but comprehensive summary of that material.
Author Si Sheppard begins with a look at U.S. efforts to read Japanese secure message traffic - codes and cyphers - that began to slowly gather momentum soon after World War I, only to be abruptly halted in 1929 by Henry Stimson, President Hoover's new Secretary of State, on the grounds that, as Stimson had famously said, "Gentlemen do not read one another's mail." Fortunately, an outbreak of realism soon followed, and in the 1930s both the U.S. Navy and the U.S. Army made important breakthroughs in intercepting and reading encrypted Japanese military and diplomatic messages. Unfortunately, their efforts were separate and insufficiently shared, both because of the sensitivity of the subject and, to a sad extent, because of inter-service rivalry.