The Minister of Defense (防衛大臣, Bōei Daijin), or Bōei-shō (防衛相), is a member of the Japanese cabinet and is the leader of the Ministry of Defense, the executive department of the Japanese Armed Forces. The minister of defense's position of command and authority over the military is second only to that of the Prime Minister of Japan, who is the commander-in-chief.
The minister of defense is appointed by the Prime Minister and is a member of the National Security Council and the National Intelligence Council. The current Minister of Defense is Shinjirō Koizumi, who took office on October 21, 2025.
Contents
History
On 26 December 2007, the Government of Japan made the decision to reform its Defense Agency to the Ministry of Defense in the expectation to have a far-reaching effect on Japan's future military development. The defense policy that has been pursued by Japan is based on the "Basic Policy for National Defense", which was adopted by the Cabinet in May 1957. Japan's main goal of national defense is the prevention of indirect as well as direct aggression from outside enemies.
The Japanese government reformed the Defense Agency to the Ministry of Defense with a ceremony that was attended by then Prime Minister Shinzō Abe and the then-new Minister of Defense Fumio Kyuma. The creation of the Ministry of Defense was in conjunction with Prime Minister Shinzō Abe's continued efforts to ensure a stronger image of the Japan Self-Defense Forces (JSDF). The bill in which to upgrade the Defense Agency to the Ministry of Defense was approved by the House of Representatives (lower house) in November 2006, and the House of Councillors (upper house) in mid-December 2006. Minister Kyuma personally attended a session in the House of Councillors and gave a speech after the bill was approved.
On 11 September 2019, Taro Kono became the first high-profile 'prime minister-ready' politician to head the Ministry of Defense. He has the strongest LDP factional backing of any defense minister thus far. His social media following is second only to Prime Minister Shinzo Abe. He's a leading candidate for post-Abe premiership. Kono previously held the prominent role of foreign minister.
Chain of command
Prime Minister
Minister of Defense
Chief of Staff, Joint Staff
Structure
The Commander-in-Chief of the Japan Self-Defense Forces (JSDF), who does not formally constitute a uniformed military, is the Prime Minister. The Emperor of Japan is a constitutional monarch who does not have political or military authority over the JSDF; that authority rests with the Prime Minister. However, the Emperor formally appoints the Prime Minister to office. The Minister of Defense is responsible for the organization and formulating the national security policy. The budget request is drafted by the Ministry of Finance and making its own legislative proposals to the National Diet.
The Minister of Defense is advised on every concern related to the duties of the Japan Self-Defense Forces by the Chief of Staff, Joint Staff.
List of ministers of defense (2007–present)
LDP
DPJ
Independent
Allied occupation of Japan
Following the end of World War II, the Armed Forces of the Empire of Japan were disbanded and US forces took control. From 1950 to 1952, the National Police Reserve led by Minister of State Takeo Ōhashi was formed. It was renamed as the National Safety Force in 1952. In 1952, the Coastal Safety Force, the waterborne counterpart of the National Police Reserve, was founded and led by the Commissioner of the Coastal Safety Force (保安庁長官) Tokutarō Kimura.
Directors general of the Defense Agency
These are the directors general of the Defense Agency. It is the predecessor of the Ministry of Defense which was established on 9 January 2007.
Tokutarō Kimura 1954
Seiichi Ōmura 1954–1955
Arata Sugihara 1955
Shigemasa Sunada 1955
Funada Naka 1955–1956
Tanzan Ishibashi 1956–1957
Nobusuke Kishi 1957
Akira Kodaki 1957
Juichi Tsushima 1957–1958
Gisen Satō 1958–1959
Shigejirō Inō 1959
Munenori Akagi 1959–1960
Masumi Esaki 1960
Naomi Nishimura 1960
Sensuke Fujieda 1961–1962
Kenjirō Shiga 1962–1963
Fukuda Tokuyasu 1963–1964
Jun'ya Koizumi 1964–1965
Raizo Matsuno 1965–1966
Eikichi Kanbayashiyama 1966
Kaneshichi Masuda 1966–1968
Kiichi Arita 1968–1970
Ministers with military experience
Although Article 68 of the Constitution states that all members of the Cabinet must be civilians, former military persons may be appointed Minister of Defense.
Raizo Matsuno - served in the Imperial Japanese Navy during World War II and rose to rank of Lieutenant commander
Yasuhiro Nakasone - served in the Imperial Japanese Navy during World War II and rose to rank of Lieutenant commander and worked as Paymaster
Sōsuke Uno - served in the Imperial Japanese Army during World War II and rose to rank of Second Lieutenant
Soichiro Ito - served in the Imperial Japanese Army during World War II and rose to rank of Second Lieutenant
Shin Kanemaru - served briefly in the Kwantung Army as Sergeant in 1937-1938 and was discharged due to illness
Satoshi Morimoto - served in Japan Air Self-Defense Force and rose to rank as Major
Gen Nakatani - served in Japan Ground Self-Defense Force as platoon leader and instructor with rank of Lieutenant