Again, literal Nazi revisionism. The invasion of Poland was mostly a peaceful process, and the only aim was to establish pro-communist forces in the area that would ensure Poland would join the USSR against the Nazis when the Nazis attacked. The same was attempted in Finland, and what do you know, Finland actually did join the Nazis during the Continuation War. And what do you know, the USSR retreated its troops from Poland after WW2.

Poland could have entered a military alliance with the USSR for the former 10 years, Stalin went as far as offering to send ONE MILLION soldiers, together with aviation and artillery, to military allies if France, England and Poland joined in a military alliance against the Nazis. But I guess they would rather see the Nazis massacre the communists first. That strategy didn't work out as planned now, did it?

They didn't want to get rid of the Nazis

This is incredibly ahistorical revisionism. The USSR prepared for the war against Nazi Germany for many years before it started. In the second half of the 1930s, seeing the Nazi rising to power (Nazis being overt enemies of Communism, as proven by what they did to Communists and to Unions in their controlled territories), they ramped up the weapon production and their military industry, and I'll say it again in case it didn't register: they spent the entire 30s seeking out military alliances with France, England and Poland against the Nazis. They offered military help to Czechoslovakia in 1938 during the Munich agreements in which Sudetenland was given to the Nazis.

Why do you think they had a NAP?

They had a non-aggression pact because Germany was an established industrial power for 100+ years at that point, while the USSR had had 19 years from 1921 after the Russian Civil War and WW1 to rebuild the country and to industrialise. They desperately needed every year they could get to reduce the industrial gap between them and the Nazis, as proven by the immense human cost to the USSR in the war against Nazis.

The Soviets literally saved Eastern Europe from an even worse fate, at immense cost of human lives (25+ million human lives lost in the USSR to Nazism), god knows how many millions more of Slavs (and other groups like Jews and Roma) the Nazis would have genocided if it hadn't been for the Soviets. Have some respect before spewing anti-communist, nazi propaganda here, please.