War in The Land of The Rising Sun

When the Japanese attacked Pearl Harbor on December 7, 1941, the US Navy had a total of 111 submarines. However, this fleet was not nearly as impressive as the number suggests. It was mostly a collection of aging boats from the late teens and early twenties, with only a few of the newer, more modern Gato-class boats. Fortunately, with the war in Europe was already two years old and friction with Japan ever increasing, help from what would become known as the Silent Service in the Pacific was on the way: there were 73 of the new fleet submarines under construction.