Continuing to elaborate amendments to the National Defense Act, Congress, in April 1938, established the requirement that line officers should not be detailed to or remain as members of the General Staff Corps unless two of their immediately preceding six years had been served in actual command of or on duty other than General Staff duty, with troops of one or more of the combatant arms or as instructor with the National Guard, Organized Reserves, or Reserve Officers’ Training Corps.[142] Two days later in another amendment to the basic act, Congress provided for establishment of a Regular Army Reserve, membership in which was restricted to persons under 36 years of age who had served in the Regular Army and from which an honorable discharge had been received.[143] The Regular Army Reserve was subject to call to active duty by the President in case of emergency declared by him. Within six months after the termination of an emergency declared by the President, the Reserve forces were to be placed in an inactive status or discharged, whichever was the more appropriate.[144] In June 1938 the 1916 statute was amended to increase the allowed strength of enlisted men in the Army Air Corps from 16,000 to 21,500.[145] That same month an earlier Naval Reserve statute (Act of February 28, 1925) was superseded and a Naval Reserve to consist of the Fleet Reserve, the Organized Reserve, the Merchant Marine Reserve, and the Volunteer Reserve was created. All were to constitute a component part of the Navy.[146] The same Act also provided for a Marine Corps Reserve.[147] The reserve units were to be composed of persons transferred, enlisted, or appointed to them.[148] But it is in 1940 that the statute books commence to reflect administration and congressional anticipation of American participation in the War and the attendant necessity to compel individuals to give military service. On May 14, 1940 provision was made for the extension of all enlistments in the active military service for the duration, plus six months in the event of war or other emergency declared by Congress.[149] The Secretary of the Navy was given power, six days following Pearl Harbor, to extend for the duration of the war plus six months all enlistments in the Navy, Marine Corps, and Coast Guard.[150] Another enactment of that date permitted the similar extension of Army service.[151] This Act also eliminated all territorial restrictions on the use of units and members of the Army.[152]