The , 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).