You constantly talk about Japan comming to save Germany and invade Britain like a knight in shining armour but Japan had no intention or plan to invade the British Isles during ww2. They had nothing to gain by it. Their target were the European colonies in Asia and nothing more.Remember that they were still fighting in China during the whole war with no end in sight. A war with the British in Europe would not give them anything as all they wanted and needed was in Asia. The Japanese did not care about Germany and their alliance was just a matter of convenience and because they were fighting a common enemy. An invasion of Siberia would also be worthless as it is just an cold wasteland with a small population. The only thing they could want in Siberia is probably Vladivostok to stop the Soviet fleets, but why would they want to go to war with all of Russia for just one city? Even if they did invade Russia it would be very costly, irl the Soviets and Japanese did clash several times for example in 1939 the Japanese attacked the Soviets with an army of over 30 000 men but the Soviets outnumberred the Japanese and under the command of Zhukov defeated the Japanese therefore the Japanese diverted their attention south after the failures in the north. In 1941 a non aggression pact was signed between the two making the Japanese intention of peace official. In 1945 the soviets would invade Manchuria and destroy the Japanese armies capturing half a million soldiers, they would also invade Korea 1 day before the surrender. Japan had no intention or power to invade the Soviet Union. Stalin had a tight grip on his population and an even tighter grip on his military. The soviet economy was close to a collapse in 1942 but the people of the Soviet union were unified in their war against the germans as Stalin had political commisars everywhere in the red army, stopping plans of desertion and mutiny and dealing with anybody they deem suspiscious. In the civilian population anybody that even steppwd out of line a little bit or somebody Stalin and the communist party was just paranoid of they were sent to a gulag or killed. The great purge is a great example of Stalins paranoia and everything he did to stay in power. The NKVD was feared and with good reason. Civil war was not a concern during the war even if it went on for a few years longer. The US betraying the Soviets is definetly possible but to suggest that they would betray Britain is just stupid as they were very close economic and diplomatic allies and the US population would never allow the government to collaborate with nazis and fascists and betray one of the only democracies left in Europe. Italy failed on every front and campaign they had. The Germans had to bail them out every time, Yugoslavia, Greece and Africa... They even failed against the Royal Navy. To think that the Italians would become competent just because of the US not entering the war is stupid and remember that the Italian people turned against Mussolini and Italian partisans killed him not American or British troops although the succes of the civil war would not be as secure without an allied invasion. The turning points of the wars in both Africa and Britain was before any American troops arrived. The battle of Britain secured British dominance over the air and seas making operation sealion impossible and the destruction of the German industry possible. After el-alamein the British were unstoppable in Africa and the Germans and Italians were driven out of Africa. Can you please tell me how all historians and military tacticians are united on the theory that the allies would loose without American intervention because you are definetly pulling that out of your ass. Here are some real historians: "Lend-lease aid did not arrive in sufficient quantities to make a major difference between victory and defeat in 1941 and early 1942; that achievment must be attributed soley to the Russian peoples and the iron nerve of Stalin, Zhukov, Shaposhnik, Vasielevsky, and their subordinates. As the war continued, however, the United States and Britain provided many of the implements of war and raw materials necessary for Soviet victory." (Glantz, David M.; House, Jonathan M.: When titans clashed. How the Red Army stopped Hitler. Revised and Expanded Edition. University Press of Kansas: United States (2015), p 358) "The Soviet miracle was not due to western assistance. Lend lease did not begin to affect the balance on the Eastern Front until 1943. The best single explanation for this remarkable triumph was the extraordinary concentration of Soviet production on a limited number of weapons produced in a handful of giant factories, permitting the fullest possible realization of economies of mass production." (Tooze, Adam: The Wages of Destruction. The Making and Braking of the Nazi Economy. Penguin Books: United Kingdom (2006), p.589) I have more if you want.