Congress, having made provision for the extension of regular service enlistments for the duration in the event of emergency, then granted the President authority to call the reserve to active duty. This was accomplished in August 1940 when Congress delegated to the President power until June 30, 1942 to order into the active military service for a twelve month period any or all members and units of any or all reserve components of the Army of the United States, and retired personnel of the Regular Army, with or without their consent, in any manner the President deemed necessary for the strengthening of the national defense.[153] The August statute having empowered the President to order the National Guard, as well as other reserve units, into active duty, it seemed desirable to equip the States with authority to set up military units for home duty in the absence of the Guard. An October 1940 statute accomplished this purpose by authorizing the states, while any part of the National Guard of the state concerned was in active federal service, to organize and maintain whatever military forces other than National Guard were believed necessary by the state.[154] These forces were subject to the Secretary of War’s regulation on matters of discipline and training. They were not subject to federal call, but neither were individual members exempt by reason of service in such units from military service under any federal law. In September 1950, three months after outbreak of the Korean War, Congress authorized the President to call up reserve forces and retired personnel from all military branches, with or without the consent of those called.[155] And, as in the Second World War, state authorities were again empowered to set up military units to substitute for the National Guard as long as any part of the National Guard was in active federal service.[156] Meanwhile the gradual inclusion of compulsory service provisions in statutes was carried to its ultimate conclusion in the Selective Training and Service Act of 1940.[157] The Act required the registration of all male citizens of the United States and male alien residents between the ages of 21 and 36.[158] The President was authorized from time to time, whether or not a state of war existed, to select and induct into the land and naval forces of the United States for training and service whatever number of men in his judgment might be required for such forces in the national interest.[159] A peacetime ceiling of 900,000 inductees was established, and provision made for a twelve months’ maximum training period subject to extension whenever the Congress declared that the national interest was imperiled.[160] The remaining powers granted to the President in the Act, and the limitations which circumscribed his exercise of them, will be discussed in other contexts.