I recently read from a history textbook about the Treaty of Versailles and the harsh conditions it imposed upon Germany. In addition to forcing the dissolution of the German Empire into the sovereign nations of Prussia, Bavaria, Hanover, and Rhineland (demilitarized at the border), Kaiser Wilhelm II was forced to abdicate, the German-ruled parts of Africa were divided up between the French, British and Belgians, and none of the newly created countries could merge with Austria (which lost its own empire).
The Prussians offered the crown to German Crown Prince Wilhelm, and he was crowned King Wilhelm III. Wilhelm reigned as a constitutional monarch with limited powers while the junkers dominated the government. Paul von Hindenburg was elected Chancellor in 1920 and held the job until his retirement in 1932. Foreign Minister Joachim von Ribbentrop succeeded Hindenburg as Chancellor.
In Bavaria, Adolf Hitler attempted to overthrow the democratically elected government in November 1923. The abortive putsch resulted in about 20 deaths, mostly of Bavarian soldiers. Seeing what a troublemaker Hitler was, the Bavarians deported him back to Austria after serving two years in jail. He was lucky. His colleagues, Ernst Rohm, Hermann Goering and Erich Ludendorff, were not and they were hung by Christmas. The ban on the Nazis from political activity remains to this very day.
Then, there was the Hanoverian Civil War which the Communists won in 1934. France and Britain were reluctant to intervene in Hanover. But when Rosa Luxemberg became President, she offered the Vice Presidency to Sudeten Communist Leader Klement Gottwald if agreed to an anschluss of the Sudetenland to Hanover.
But her belligerency towards Prussia was the last straw. An attempted Marxist revolt in Danzig started the war in 1936. It was no contest. The Prussians had the superior military thanks to Erwin Rommel. After six months of war, Luxemberg was captured, tried as a war criminal and hung in the public square. Former Defense Minister Karl Doenitz became President of post-Communist Hanover. Rommel would become Chancellor of Prussia and retire in 1958.
What became of Hitler? Back in Austria, he wrote a book of his experiences as a prisoner titled My Struggle (Mein Kampf). The book sold only a few thousand copies and proved to be a piece of trash. Hitler turned to the bottle and finally snapped after the death of his niece Geli Raubal. He committed suicide by swallowing cyanide pills.
What if France and Britain decided not to break up Germany? If Woodrow Wilson survived his heart attack in 1916, would he have convinced the Allies not to punish Germany that harshly?
Wilson's successor, President Thomas Marshall was reluctant to take a leading role in the post-war negotiations. The United States was weary of war and wanted to stay out of European affairs. Nevertheless, the Senate approved the Treaty of Versailles.