Germany starts the policy of unrestricted submarine warfare in January 1915. Later that month German Foreign Minister Gottlieb Von Jaglow fires off a telegram to the Ambassador in Mexico City asking to propose an alliance if the US goes to war against Germany and offering territory lost in 1848 as compensation. In April 1915, Wilson goes before Congress and asks the world be made safe for democracy and declaration of war against Germany passes both houses. In May of 1916, the AEF assembles in France. Germany fighting a two front war collapses in September 1916. The victory ensures Wilson's reelection. There is no Russian Revolution, at least not in 1917. There are Czarist Russian diplomats at Versailles. I think they want the treaty even harsher. So what happens?