What if the Soviets had joined the Axis in the WW2? A detailed alternate timeline! (Part 1 of 3)

This video is sponsored by Call of War, a free to play multiplayer strategy game: 💥 Click here to get an amazing New Player Pack, available for the next 30 days only! Only newly registered players are eligible for it. Imagine World War 2 going a different route. Imagine German and Soviet pact of 1939 being just the beginning. There is no Operation Barbarossa. But a true alliance is formed instead, with Soviets joining the Axis forces. Could they change the tide of the war? What would such a conflict look like? due to the complexity, this is just the first part of a 3-part series. Image elements used in the thumbnail: T-34 by Topory, CC BY-SA 3.0 , via Wikimedia Commons