There was considerable debate in Marxist circles before the Russian Revolution as to whether Russia could have a proletarian revolution or not. Whether it should limit itself to a bourgeois revolution, like the French one. Marx being the scientist that he was, was open to the possibility; as we couldn’t know for sure, in advance, that it wasn’t possible.
However, given the fact that workers made up probably less than 5% of the population, a pure workers’ revolution didn’t seem realistic. But could an alliance with the peasants, rather than the emerging capitalist class, defeat the feudal class of landowners & continue to communism rather than stopping at capitalism? Trotsky, who was initially a Menshevik, not a Bolshevik, thought so & his theory of permanent revolution won over Lenin, who was initially sceptical. Lenin knew though that Russia could only be the ‘weak link’ in the world economy & that ‘socialism in one country’ wasn’t a possibility. The revolution had to spread, preferably to Germany, France & Britain for it to be successful. It didn’t, largely due to the reformism of the Social Democratic Party in Germany & the Labour Party in Britain. Not forgetting the involvement of British & other foreign troops in fermenting civil war.