In the cold war era, Japanese political leaders decided most of defense policies without providing the military expert advice, so they seldom met with the military officers. The Internal Bureau supervised the Self-Defense Force (SDF) that consists of the Ground Defense Force (GSDF), Maritime Self-Defense Force (MSDF) and Air Force Self-Defense Force (ASDF). The Internal Bureau was responsible for defense policies with the SDF. In other words, the Internal Bureau's main role was not operation of the SDF but management of it, such as the defense build up plan and the administration of personnel affairs. Political leaders formally controlled the military.
In the post cold war, the security environment surrounding Japan has changed defense policy considerably. The SDF missions and roles has expanded. Thus, the Ministry of Defense (MOD) has reviewed “Positioning of Missions”. Defense of Japan 2007 says, “Among those operations historically positioned as Supplementary missions, the following were stipulated as primary missions.
1) Activities that contribute to maintaining the peace and security of the international community including Japan, including international disasters relief operations, international peace cooperation operations, operations based on the Anti-Terrorism Special Measures Law, and operations based on the Law Concerning Special Measures on Humanitarian and Reconstruction Assistance in Iraq.
2) Activities conductive to ensuring the peace and security of Japan in situations arising in areas surrounding Japan, such as rear area support and other activities based on the Law concerning Measures to Ensure the peace and Security of Japan in Situations in Areas Surrounding Japan and ship inspection operations based on the Ship Inspection Operations Law.
3) Activities to ensure the safety of the livesand property pf the Japanese People, such as minesweeping and the evacuation of Japanese nationals abroad.”
Organization of the MOD/SDF has changed to coupe with various missions. The MOD has reconstructed its internal bureaus in order to make various policies. It goes without saying that the SDF has been reconstructed.
It is clear that political leaders, such as the Minister of Defense can't decide defense policies without the military expert advices. The Chief of Joint Staff Office and the Chiefs of Staff for the GSDF, MSDF and ASDF are military expert advisors to the Minister. So, Civil- Military relations has been changing in Japan.