You missed the part in between where they made a deal with the nazis

I didn’t miss that part because there was no “deal with Nazis”. Nothing as bad as the Munich Agreement signed the previous year by England, France and Germany among others, allowing Hitler to occupy the Sudetenland, a land with more than 3mn people in Czechoslovakia (to whom the Soviet Union offered assistance but Romania and Poland denied pass to Soviet troops, possibly influenced by the fact that Poland also did a grab of land of Czechoslovakia). The USSR spent the entire 30s trying to push for a military alliance with England, France and Poland to stop Nazism, but they all refused because a good liberal would rather have Nazis first exterminate communists. Stalin went as far as offering to station 1 million troops, together with aviation and artillery, in France, in case Stalin invaded, to which England and France refused. Feel free to study the so-called “collective security policy” pushed by the USSR in Europe against Nazism.

The Soviet Union had been in a civil war until 1921 (right after a devastating WW1/, and before that it was a preindustrial nation. It had a whopping 19 years to rebuild the country from scratch and to industrialise, compared to the 100+ years of German industrialization. They desperately needed every single year of industrialization they could get in order to gain some advantage against the industrially superior Nazis, as evidenced by the 25+ million casualties the USSR suffered against the Nazis despite material help from the US. Making an agreement to postpone the war after every country in Europe refuses to enter a military alliance against Nazis just because you’re a communist country, is just the logical action to defend your citizens.

Please stop pushing revisionist nazi propaganda. Without the USSR, the slavic population of Europe, including Polish, Ukrainian, Belarusian and Russian, as well as many other ethnic groups, would have been genocided in vastly superior numbers than they were.