The Korean War broke out on 25 June 1950 (Showa 25). With the urgency of the war situation and the dispatch of numerous American troops who had been stationed in Japan, General MACARTHUR addressed a directive to YOSHIDA Shigeru on 8 July approving the creation of a 75,000-person National Police Reserve in Japan and an 8,000-person expansion for maritime safety. On 10 August the Japanese Government promulgated and put into effect the Police Reserve Act, within the framework of the Potsdam Declaration.

On this point, ASHIDA Hitoshi expressed his concerns that under the current Constitution, the fact that such an important decision had not been made by legislative process would isolate the National Police Reserve and National Diet from each other in the future, rendering any affinity impossible with the people. Also, he wrote of the necessity of making it clear that the National Police Reserve in the future would be considered as army.