Before WW2 ever started Europe was full of complicated, strange, and a few pointless treaties and pacts. Now while some are notable- Treaty of Versailles, Treaty of Brest-Litovsk, etc. there are some that are truly weird. The biggest culprit of confusing treaties in Europe at the time was probably the newly formed USSR and its predecessor the Russian Empire. The alliances of WW1 could not have possibly been more strange then Britain, France, US and the Russians, but somehow through a massive bundle of Cyrillic written paperwork the Russians sucked it up and took it hard from the Germans until Lenin signed off a nice chunk of the largest continuous empire on earth at the time. Finally in 1939 the Russians made a pact that actually makes sense to regular people- The Nazis and the Soviets would not attack each other. Of course in our OTL the pact was broken when Hitler got a little ballsy and shortly afterwards was ground into the pavement of central Europe by the Soviets. The POD for this timeline is that Nazi Germany doesn't invade the Soviet Union in 1941 and instead focuses on taking war one front at a time. Of course the Nazis will invade the USSR, but it won't be until much later...
Timeline:
1939: Nazi-Soviet non-aggression pact takes effect, Germany invades Poland and Galicia, While the Soviets annex the Baltics. Stalin invades Finland with help from the Nazis who received help in taking Galicia.
1941: All is going well for the two new European superpowers- Germany has dominated France with the British unable to mount a significant offensive in retaliation, while the USSR has taken the Baltics with ease, and Finland's southern border has been added as a buffer to Leningrad. Pearl Harbor is not attacked.
1943: Nazi Germany launches a MASSIVE amphibious landing of the UK, which is taken in a matter of months, the colonies of the western colonial powers now belong to Germany. This angers Stalin and the USSR who support anti-colonialism movements in Africa and South Asia, the NKVD begins to support guerrilla wars in the countries surrounding the USSR.
1944: The USSR is beginning to feel the threat of an invasion on all borders, meanwhile the Japanese feud with the Germans as to who owns Indochina, it is decided that Cambodia is a German colony while the Nazi-Japanese relations are becoming strained.
1947: Many people in what is now a Nazi occupied west Europe flee to the USA; meanwhile the Japanese decide to invade the Soviet Union to expand the empire, the Germans decide to stay out of the invasion of east Europe for the USSR now has a heavily militarized border that the Germans dare not assault. The invasion effectively cuts the ties between the Nazis and the Japanese.
1948: With most of the non-Aryan population fled or killed by the Nazis, the Soviets attempt to build better weapons to outclass the Nazis- they make two breakthrough discoveries: 1. The new Soviet Tanks are equipped with sloped armor which deflects most incoming rounds, and 2. The Soviets develop the first ever battle helicopters with the help of Nicolas Florin (Russian born engineer returned to Russia to escape Nazi persecution) leading the project, they develop the first combat helicopter, equipped to carry eight men- one pilot, one gunner, and six soldiers. The Nazis, however, have nearly perfected the atomic bomb.
1949: Japanese forces are delayed as the Soviets sabotage the Trans-Siberian railway in the city of Omsk, causing the Japanese to leave Siberia suffering huge casualties trying to return home, at the same time the Japanese decide not to even try and support the Nazi invasion of the USSR, which has been tilting in favor of the Soviets. The Soviets decide to launch a full scale offensive through Finland in order to take the Nazis by surprise, and abandon the Baltics; that winter the Nazis suffer brutal casualties as the Soviets retake the Baltics and Leningrad in one swift move with Operation: Uranus.
1951: After two years of brutal fighting on the eastern front the Nazis have tested and used their secret weapon - the atom bomb. However, Soviet AA guns keep the bomb from being deployed effectively and as a result the Nazis nuke the Soviet stronghold at Warsaw, Poland. The Soviets then copy the technology and drop their atomic bomb on Vienna in the Greater German Realm. Hitler Launches operation Valkyrie but moves the capital to Brussels, Belgium. The Nazi occupation of Eastern Europe has ended and the Europeans are grateful to the Soviets.
1953: The empire of Japan has lost many troops to the bitter Siberian winter and to guerrilla warfare used by the Chinese and Indochinese. The Nazis have lost their eastern buffer, and surrender to the Soviets. The Japanese however continue the war by trying to invade through an island hopping campaign focused on the Diomede Islands. The USSR retaliates with an invasion of the Diomedes and the United States sells Alaska to try and cut down some of the debt it hasn't been able to rebuild from.
1954: WW2 is now over and Stalin has passed away. Western Europe is VERY bitter towards the USSR not trying to save them, however they are grateful for being liberated. Communist regimes are established but the colonial possessions are lost, leading to anarchy in many new countries, however Canada receives support from the United States which is finally recovering from its economic crisis. The USSR has annexed all of Finland, and it European borders reach the maximum extent of the OTL otherwise. Germany has no aid from the United States and the USSR is free to have its way with the technology produced in Nazi Germany including advancing the Hydrogen bomb, building upon the intermediate assault rifle, and consumer products such as cars. The USSR also forces Japan's Surrender and commandeers its navy, advancing it and creating a significant Pacific fleet. Western European States are down in their own economic recession however the new structure of the Soviet command economy that has been put into place has helped soften the blow.
1960: Several Western European States have rose up against the USSR's dominance however they are rather unsuccessful in ridding themselves of the command economy and Soviet presence. In secret the European Union has been formed and has declared independence from the Soviet bloc, the United States and the USSR recognized the independence of the European Union however the Soviets are reluctant to do so. The United States has been developing its own Nuclear weapons program in collaboration with western Europe since 1956, the rebellions in Western Europe have been put down mostly, but there is still unrest and the western bloc still pushes for true independence; still eastern countries are distrustful of the west and lean more towards the Soviet economy, leaving Europe split along the Czech-Slovak border.