I actually had a argument over this,here's the possibility. World War I becomes a stalemate,because the United States comes to the defense of Germany,Austria-Hungary and the Ottoman Empire. The British tried to convince America to be on their side,and they did..but barely.
This idea that America comes to be an ally of Germany,comes from the fact that around 1918 and shortly before..there's a huge influx of German immigrants in America,and the Irish-Americans want to use this as an excuse for Ireland's independence.
The German Empire survives,but at the cost of loosing all of it's colonial possessions to Britain. But at the same time,there are some mixed feelings about all of it..
Russia suffers staggering losses at the front,and Czar Nicholas II avoids the February Revolution by actually being there instead of else ware. Lenin is executed instead of being exiled to Siberia,the only consequence is that Russia becomes a Constitutional monarchy after the war,a congress (Duma) runs things..but with the Czar's approval..because before,and even during the war..the Russian people still respected their ruler.
The worst off being the Ottoman Empire,which is barely being held together. Aid soon comes in from the victorious Germany and United States,along with the morale boost that came from winning the war. One huge point of argument is that possibly with the Ottomans still in control,the Middle East does not descend into chaos..like it naturally did in real life.
What do others think would have happened if the Central Powers,with America won the war..or caused stalemate?