military authorities; army circles
Refers to the military establishment as a political or institutional force, especially in prewar and wartime Japan. Often used in historical or political discussions.
At that time, the military authorities had strong influence over the government.
The policy was changed under pressure from the military.
In the early Showa era, the military authorities rapidly rose to political power.
The government caved to pressure from the military authorities and changed its policy.
軍事 means 'military affairs' in general, while 軍部 refers to the actual body of military authorities as a political force.
military dictatorship
Compound of 軍 (gun, 'military') and 部 (bu, 'section' or 'department'), literally 'military department'. The term gained prominence in early 20th-century Japan to refer to the military as a political force.