Suppose a WWI scenario circa 1914 with more or less the same borders (except that Germany never took Alsace-Lorraine) that pits an alliance of Germany, Russia and Austria-Hungary against an alliance of Britain, France, and the United States. What other countries might join in? Where would the fighting take place? Who would win?
I have no specific POD in mind, so don't ask. Just brainstorming, really.