Imperial Japanese Navy - World War II

World War II

The IJN of World War II was administered by the Ministry of the Navy of Japan and controlled by the Chief of the Imperial Japanese Navy General Staff at Imperial General Headquarters. In order to combat the numerically superior American navy, the IJN devoted large amounts of resources to creating a force superior in quality, the objective being of "making up for quantity by means of quality". Consequently, at the beginning of World War II, Japan probably had the most sophisticated Navy in the world. Betting on the agile success of aggressive tactics (stemming from Mahanian doctrine and the lure of "decisive battle"), Japan did not invest significantly on defensive organization: she needed to protect her long shipping lines against enemy submarines, which she never managed to do, particularly under-investing in the vital role of antisubmarine warfare (both escort ships and escort carriers), and in the specialized training and organization to support it.

IJN enjoyed spectacular success during the first part of the hostilities and completely drove out the Royal Navy from the East Asia, but American forces ultimately managed to gain the upper hand through technological upgrades to its air and naval forces and a vastly greater industrial output. Japan's reluctance to use their submarine fleet for commerce raiding and failure to secure their communications also hastened her defeat. During the last phase of the war, the Imperial Japanese Navy resorted to a series of desperate measures, including a variety of Special Attack Units (popularly called kamikaze).