It's often said that the war was won with British intelligence, American steel, and Soviet blood.
I'm sorry? They went from a peasant society immediately to defending against multiple foreign invasions (including the U.S.) to fighting and defeating the fascists, all in three decades. That was achievable only due to their economic and political system.
This is old, debunked propaganda trope recited for a millionth time.
No, USSR never went to industrial giant overnight, for a reason it never been it. USSR relied on single digit of large factories for everything during the war.
Even tiny Eastern European countries USSR invaded were heads above USSR, to the point the first thing USSR did there were stealing all factory equipment, and relocating it to new factories in USSR.
So arguably it had nothing to do with the largest war of all time waged against them explicitly for their annihilation?
Very arguably, as it's actually the opposite: the socialism forced mass force industrialization, and prepared USSR better for WWII than Russia ever had any chance of being.