One insight into Lenin's struggles with Communism after the war can be seen in his tentativeness to secure a solitary economic policy for Russia. Through the establishment of War Communism, then the New Economic policy, then the situation with Germany that would provide fertile ground for the power struggle between Stalin and Trotsky; it would seem as though the strict Marxist ideal for Communism had lost its novelty for Lenin. Despite the wonders one might have as to what ideological changes occurred between his return from exile to his death in 1924, one thing is certain: circumstances had been as influential a force on Lenin's politics as Marx. In terms of how these forces played a role in his struggles after the Civil War, they can be encapsulated with his inconsistent policy changes and deals with Germany.
In a way, this atmosphere of Communist unease can be seen to have lead directly into the Stalin-Trotsky power struggle. At its heart, the power struggle was the result of a fundamental divide surrounding how to properly understand Communism: Does Communism represent a devotion to the state and the people (as represented by Trotsky and his pledge to increase food production)? Or does Communism represent a devotion to the integrity of the state and its political character (as represented by Stalin's pledge to increase the military strength of the Soviet Union)? In a strange eventuality that remains as much a statement about Political Philosophy as it does the Russian revolution, one position stood superior to another not because of its conceptual eminence but rather the force it employed in its own support. The brute force Stalin used to muscle his way into leadership, and end his debate with Trotsky, seem both to follow quite logically from the content of the beliefs themselves.
Did Stalin modernize Russia? I would argue that he didn't, and I don't see any greater support than the fact that his "Socialism in one country" seemed such an antiquated notion at this point. Antecedents of notions of this kind had been seen with concepts like Isolationsim, and not only did those policies prove to be unfruitful due to the increasingly international nature of politics, they could never be sustained indefinitely. Indeed, one might see Stalin's point of view on Russia's interactions with the world as the cause of the seriousness of the battle of Stalingrad. It simply follows suit that these beliefs would manifest themselves in other aspects of the Soviet regime, namely Stalin's absurd notion of Economic progres