The Soviets were quite open about aiming for world conquest, starting with Europe. They tried it first in 1920, but Poland miraculously defeated them. WWII was another attempt (had Hitler not attacked first, Stalin would probably just attack Germany within a short period of time) - first Poland and Germany, then France, Spain, Italy, UK etc. It only stopped at Poland and Eastern Germany that time because of strong backing of the US for the Western Europe.
The Soviets were not bent on world conquest, but on securing a ring of buffer states around them as security for their country. Witness Stalin's betrayal of the communists in Greece as horse trading for influence elsewhere. Stalin's socialism in one country policy set against exporting revolution was in fact a huge point of contention with other factions of the Bolsheviks.
While the Soviets did harbour imperial ambitions against neighbouring states (Poland, Finland), this:
> had Hitler not attacked first, Stalin would probably just attack Germany within a short period of time
is blatantly false, and insultingly so given the millions of Soviet citizens who paid a bloody price for Stalin's total lack of readiness at the German border or mobilization against the Nazis.
Actually, it is pretty well documented that Germans forestalled Soviet offensive by just few weeks, maybe months. Red Army’s initial misfortunes after Germany’s attack in 1941 were caused by the fact that all the troops they had in proximity to USSR-German border were preparing to attack, not to defend themselves.
> it is pretty well documented that Germans forestalled Soviet offensive by just few weeks
No it's not. The only “Historian” to say so was the so-called Suvorov, a transfuge of the NKVD. And his theories have been thoroughly dismantled by the whole academia.
While Stalin might have wished to invade Germany in 1941 or 42, he was in no position to do so, having recently liquidated most of the Red Army's leadership.
