Leninism vs. Trotskyism: What's the Fundamental Difference?

So what was that '20s debate in the Soviet Union about anyway and how do modern communists relate to it? The two basic perspectives that were dominant therein were Leninism and Trotskyism, so let's get into what those respectively are/were a bit, since they're often confused for one-another:

Leninism consists of some main components including the recognition of imperialism as the final stage of capitalism, the corresponding labor aristocracy theory, democratic centralist vanguard organization, a strategic alliance between all the working people of a society (the proletariat, the peasantry, and the various middle strata) led by the proletariat and peasantry, and the centrality of revolutionary councils and committees to at least the early stages of socialism. Lenin believed that it was possible and desirable for the proletariat, through the aforementioned class alliance, to seize state power even in backward, underdeveloped countries like Russia, and to, from there, develop a mixed economy -- an economy with a mixture of socialist and capitalist attributes -- until such time as the proletariat became the majority of the society by way of the natural workings of capitalistic development: the more bourgeois forces in society gradually running the peasants off their land in order lay the foundation for urbanization. The strategic alliance of all working people would be maintained through the course of all this, and eventually the proletariat would naturally come to be a majority therein as its ranks grew with the development of the economy. Such was the basic idea. Many modern Leninists confuse the Stalin era with representing the application of classical Leninist views. Actually, Lenin was deeply stagist, and fairly dogmatically so. His views roughly corresponded to those which Bukharin voiced at the end of the 1920s and can be justly summed up in Bukharin's slogan for developing socialism "at a snail's pace". Lenin sought a gradual development of socialism in backward countries, seeing said gradualism as necessary in order to maintain a mass base of support for the revolution itself. As such, Lenin more or less mentally associate the objective factor and the subjective factor as inextricably and absolutely linked and inseparable. In Lenin's view, almost every peasant was destined to maintain a narrow, traditionally-peasant outlook on the world, favorable simply to their own further enrichment rather than to the abolition of all exploitative and oppressive relations...etc. The ideological difference between Leninism (a.k.a. Bolshevism) and Menshevism was the difference between whether or not the proletariat should seek to seize state power in the here and now or whether instead this task should be relegated to the distant future, after the bourgeoisie have completed a long period of capitalist development that has placed the proletariat in the majority of society. The latter view was that upheld by the Mensheviks. While still upholding the classical view that a 30 or 50 year-ish transitional stage of development loosely corresponding to the bourgeois-democratic revolution would be required in countries like Russia, the Bolsheviks believed the task of achieving the bourgeois-democratic revolution and carrying it out could be done in an effort led by the proletariat, without bourgeois political power. The proletariat, the Bolsheviks contended, would not seek to develop a full-fledged capitalist economy through this revolution, but would seek to maintain a mixed economy, with the balance of economic and political muscle therein gradually swinging more and more toward the socialist component. Some people confuse the period of emergency 'wartime communism' with the actual Leninist strategy. That was an emergency policy. The New Economic Policy essentially was Lenin's strategy for getting to socialism. The NEP wasn't an ideological compromise of Leninism; it was classical Leninism in practical application. Stalin's move away from the NEP was originally conceived of as another sort of emergency policy, corresponding to the ostensibly forthcoming end of capitalism worldwide. The more distinctly Stalinist flavor of Leninism was only developed from the mid-to-late '30s. So anyhow, the Bolsheviks developed party organization according to their revolutionary approach and the Mensheviks according to their more gradualist approach.

Trotskyism consists of positions similar to Leninism, but differs with it in one key area: the mass basis of the proletarian state. Trotsky argued that the proletariat, upon achieving state power, would "be unable to contain itself" even generally to the historical tasks of the bourgeoisie and thus would inevitably need to press on to socialism upon the achievement of the basics of the democratic revolution, rather than more or less waiting around for another generation or two until such time as the proletariat was in the majority of society. Trotsky's view of party and societal dynamics was, well, more dynamic than that of the Leninists. He believed there existed real contradictions of class alignments within the Bolsheviks that corresponded to the existing classes within the society; there were, in Trotsky's view, Bolsheviks ideologically aligned with the peasants and Bolsheviks ideologically aligned with the proletariat, among other things. So the party was somewhat less monolithic and more plagued by contradictions in the Trotskyist view, and the task was to take the correct alignment. This meant insisting on always continuing the forward momentum of revolution. That may sound all well and good and even perhaps more essentially comparable to the Maoist outlook and orientation than the classical Leninist perspective, but here is the key issue: whereas the Maoist permanent revolution theory is built upon the foundation of the mass line...that of scientifically-founded trust in and unity with the broad masses of society toward a non-antagonistic reconciliation...the Trotskyist permanent revolution theory, by contrast, is rooted in profound distrust of most of the world's oppressed and exploited majority and takes a corresponding expression. According to the Trotskyist perspective, it is not possible to maintain a permanent united front with the non-proletarian classes. Rather, even in countries wherein the proletariat finds itself a relatively small minority, the proletariat must face off against even the broad masses of peasants that may constitute most of the population. You implement "socialism", in other words, by way of more or less imposing the rigors of 'wartime communism' on the peasants indefinitely; seizing all their surplus output for use by the military and by urban dwellers. Being that this "hostile collision" (being a sort of military exploitation of the peasantry) eliminates the mass basis of proletarian rule in recently-feudal countries (like the Soviet Union at the time), the Trostkyists thus would have the socialist state rely fundamentally on external help; upon "proletarian revolutions" in more developed, imperialist countries wherein allegedly "the proletariat" formed the majority of society already or (again, allegedly) at least was much more nearly in the majority. This makes for a sort of weak, dependent, authoritarian, and frankly exploitative (and thus clearly non-proletarian) 'bailout socialism', if you will.

Classical Leninism may not exactly have been without flaws, but at least it rooted itself in a sort of mass basis! Was that mass basis sufficiently wide? No. Was the classical Leninist outlook terribly dynamic and realistic by comparison to Maoism (or even, in some ways (as explained above), to Trotskyism)? No. Might the complement of a permanent revolutionary theory rooted in a mass basis have been a positive and worthy addition? Certainly! But here is the main point: without a mass basis, what you were inevitably left with as a vision of "socialism" was a nightmarish, warped, oppressive and exploitative puppet state. Or, in other words, you are left with a new variant of the old society. At least classical Leninism was comparatively mass-based.