The Imperial Japanese Navy is the maritime arm of the military of the Empire of Japan and, as of 2012, is the world's third-largest behind the United States Navy and the Marine Imperiale. In the 1960s and 1970s, it was the largest navy in the world and employed more enlisted men than any military arm of any other nation in the world. The IJN has traditionally been regarded as Japan's greatest military asset and is held in exceptionally high esteem in Japan. Between the end of the Formosa Rebellion in 1942 and the Philippine War in 2004, the IJN served exclusively as peacekeeping and did not become engaged in any major conflict.
The IJN also contains the Imperial Japanese Navy Air Service, the Imperial Japanese Navy First Response Group, the Imperial Japanese Navy Sea-to-Land Division, and the Imperial Japanese Navy Nuclear Division.