which replaced GHQ. Relations between GHQ/AGF and the Armored Force were distant, and lines of authority and responsibility were often unclear. McNair seemed to prefer leaving Devers alone. When Devers took command, the Armored Force had two operational armored divisions: the 1st Armored Division at Fort Polk, Louisiana, and the 2nd Armored Division at Fort Knox, as well as one independent tank battalion, the 70th Tank Battalion at Fort George G. Meade, Maryland. Both divisions participated in the large-scale war games of the Louisiana Maneuvers in August and September 1941 and the Carolina Maneuvers in November 1941. Despite some successes, the maneuvers revealed armored unit and equipment operational deficiencies, as well as a general lack of combat readiness. Devers attributed much of the poor performance to poorly-trained junior and staff officers but also saw doctrinal deficiencies, which hampered the co-ordination of tanks, the infantry, and the artillery. In particular, post-maneuver reports emphasized the vulnerability of tanks to antitank fire. That bolstered the antitank gun, which were strongly supported by McNair. Devers differed by countering that the number of tank "kills" credited to antitank gunners was unrealistic and biased and felt that "we were licked by a set of umpires' rules." McNair continued to push for an independent tank destroyer force, but Devers argued that "the weapon to best the tank is a better tank." Nevertheless, in November, Marshall authorized creation of a tank destroyer force. The Tank Destroyer Center was created, and the War Department ordered the activation of 53 tank destroyer battalions. Battlefield experience would prove that Devers was correct. In combat, most tanks were knocked out by other tanks, and tank destroyers were mainly used as mobile artillery support. The tank destroyer program was scaled back, and tank destroyer battalions were deactivated. At the end of the war, the tank destroyer quasi-arm was disbanded. Before Devers' arrival, Armored Force doctrine emphasized light tanks weighing no more than . American doctrine held that tanks were for exploitation, not fighting other tanks. He rejected the M6 heavy tank and recommended to McNair for it to be canceled, citing concerns about its weight, mobility, and reliability, which was seen as support for that position, but Devers wanted a medium tank, preferably by mounting something like a 105mm howitzer. He was appalled to find that the Armored Force's tanks were armed with nothing heavier than a 37mm gun. A new medium tank