Japan Maritime Self-Defense Force
![](/Images/godic/202501/21/Naval_Ensign_of_Japan.svg5648.png")
![Naval battle of Dan-no-Ura in 1185](/Images/godic/202501/21/DanNoUra5648.jpg")
![A 16th-century Japanese atakebune coastal warship.](/Images/godic/202501/21/Atakebune25648.jpg")
![The British-built Ryūjō was the flagship of the Imperial Japanese Navy until 1881.](/Images/godic/202501/21/Japanese_Ironclad_warship_Ryujo5648.jpg")
The Japan Maritime Self-Defense Force(海上自衛隊Kaijō Jieitai), or JMSDF, is the naval branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. It was formed following the dissolution of the Imperial Japanese Navy (IJN) after World War II. The JMSDF has a fleet of 154 ships and 346 aircraft. Its main tasks are to maintain control of the nation's sea lanes and to patrol territorial waters. It also participates in UN-led peacekeeping operations (PKOs) and Maritime Interdiction Operations (MIOs).