Nonaggression pact is not an alliance

He was never an ally to Nazis. That's ahistorical. He signed a non aggression pact, just like all the rest of the powers at the time.

And he was the last one to do it, because he was begging the UK and France for an alliance against Germany.

ordered the execution of a German deserter for "misinformation", though it is unclear if this refers to Liskow or another German deserter

This is completely ahistorical. The entire reason Stalin signed the treaty is because he knew Hitler would attack the USSR eventually, and they needed time to prepare and also didn’t want to fight a war on two fronts (because the red army was busy saving China from the Japanese).

His only choice was to sign a treaty with Hitler, because Britain and France refused to become allies with Stalin. Britain and France thought it best to let the communists and fascists fight it out and hopefully destroy each other.

Stalin signed a non aggression pact and then began rapidly industrializing his country, knowing dman well that Hitler would eventually break the treaty.

Then Stalin defeated the Nazis.

By "divvy up Poland", you mean "soviet land that Poland took in the early 1920s", I'm sure.

Your knowledge of history seems entirely non existent, besides "enemies of my capitalist imperialist genocidal empire are bad and have always been bad, despite literally saving the world from the Nazis"