In 1914 the Germans could see Paris in the distance. For reasons I have not been able to deduce, the German army turned and exposed its flank to Paris. Had the Germans not made this blunder and continued on to Paris, history very well would have been quite different. Up to and including no Hitler.....
History is super interesting!
The Germans were stopped from Paris in WWI. Then they were pushed back into a band of land 50-75 miles wide and kept there in a stalemate for years until their defeat.