27th March - 2nd April 1922: With a small margin, Leo Trotsky became first General Secretary of the PCUS, beating Josef Stalin. Trotsky previously emerged victorious in the debate against Frunze about the future policies of the Red Army, then he allied with Bukharin convincing him Stalin wasn't to be trusted and promising him to revise together the NEP. Lenin wasn't fully convinced of the idea to keep Stalin under control, but he gave his green light anyway for the election of Trotsky. Stalin secretly bowed revenge...
28th October 1922: the King of Italy Vittorio Emanuele III accepted to sign the decree of emergency proposed by first minister Luigi Facta to stop the Fascist attempt of coup. In the next hours, detachments of soldiers and policemen raised barricades on the main entries to Rome. Caught unprepared, the various groups blackshirts routed away; hearing the bad news coming from the capital, Mussolini barely escape to Switzerland. In the next days, Fascists supporters were arrested all across the country while the PNF was declared illegal.
9th November 1923: During the skirmishes between Nazis and Bavarian policemen, a straight bullet hit in front Adolf Hitler, killing him instantly. The Nazis opened the fire, but the policemen reacted killing many people including also Erich Ludendorff. Ernst Rohm, hearing the bad news, surrended hoping to have clemency, but the high military spheres in Berlin were furious with the Nazis culpable to have involved Ludendorff in their schemes. In the next months, the most involved in the coup as Rohm received high condemns, while the NSDAP was declared illegal and the SA disbanded, while few prominent Nazis such as Himmler and Goebbles escaped in Austria.
21th-22th January 1924: In the hours following the death of Lenin, Stalin and some supporters tried to overthrow the Politburo, but he was discovered and forced to escape from the Soviet Union. A newly appointed triumvirate composed by Trotsky, Bukharin and Zinoviev was de facto the controller of the USSR...
Ok, so I gave here the three/four POD which butterflied the rise of Fascism in Italy, Nazism in Germany and Stalinism in USSR. Democracy will be reinforced in Europe or other authoritarian movements could rise? It could be the golden opportunity to promote the world revolution in the name of Communism? Or the USSR will fall miserably? I hope the start I give here could be stimulating enough for a collaborative project, and many decided to jump the vagon to rewrite together the history of XXth century...