Fan Casting Justice Society of America

Later, it was discovered why the JSA, which had powerful characters, did not simply invade Germany and end the war: during the conflict, the entire European Theater of Operations was under the mystical barrier. Mystical or magically susceptible characters came under the Führer's sway, and ordinary metahumans had their powers temporarily cancelled. This barrier was created by the occult Dragon King in Hitler's service, using a machine powered by the Holy Grail and the Spear of Destiny.