The highest comment with the suggested sort for me currently is:
the soviet union wont ww2. the us just made a shitload of money, created the CIA, nuked civilians to scare russia, and set the foundation for the military industrial complex to essentially run the country. read a book.
the "Soviets were going to attack" defense for the nazis is just a nazi lie. but what i want to know is why would that fucking matter to anyone discussing this now? only a nazi defends the concept of nazi "self-defense" in the knowledge that all europe, soon the americas, and the soviet union all fought these guys while the nazis were committing the worst atrocities in history. if the soviets entered the war earlier it would've been a good thing.
but to be clear the lack of military preparedness on the border, besides disproving allegations of invasion-preparation, is one of the chief military blunders of the 20th century. there really is no excuse for so many soldiers and equipment (and it wasn't that antique or terrible equipment, the germans were running a lot of older shit too) to be lost so quickly, through the failure to deny german intelligence and initiative.