When a big war like World War I ends, the servicemen do not immediately return home. There is a long period of processing and transporting thousands of men back to the U.S. There is also the question of occupying conquered countries and enforcing the terms of surrender. No doubt the American government wanted to maintain a presence in Europe after going to the huge expense of sending a large army over there. It is a complicated and slow process. Krebs could not return to the United States until his division of the Marines was sent back from Germany in 1919.
He enlisted in the Marines in 1917 and did not return to the United States until the second division returned from the Rhine in the summer of 1919....There is a picture which shows him on the Rhine with two German girls and another corporal.
In the meantime many other soldiers were being mustered out and sent home. Just because the Germans had surrendered did not mean that all the Allied armies could automatically turn around and go home. Evidently Germany was not occupied after World War I, as it was in World War II for many years, but troops were stationed along the Rhine river, which marks the western boundary of Germany. Presumably there was a chance that the Germans might break the peace treaty and invade France again if there was nothing to prevent them from doing so. The military rule had to remain in force until a stable new German government had been established. Unfortunately the new order in Germany did not last very long. By the mid-1930s Hitler was coming into power and he had grandiose plans involving a much greater war than World War I had been. Krebs had no choice about when to come home. He was just obeying orders. He was only a corporal. He couldn't ask questions and wasn't given any information.