The great enemy of the Church—the prince of this world—has found socialism a worthy tool for many years (so clearly warned against in the 1878 encyclical on socialism by Pope Leo XIII, Quod Apostolici Muneris) and socialism’s predilection for violence is congruent with Satan's hate for humanity.
The essential book, The Black Book of Communism: Crimes, Terror, Repression, notes the strategy favored by Lenin.
“Lenin’s primary objective was to maintain his hold on power for as long as possible. After ten weeks, he had ruled longer than the Paris Commune, and he began to dream about never letting go of the reins. The course of history was beginning to change, and the Russian Revolution, under the direction of the Bolsheviks, was to take humanity down a previously untraveled path.
“Why should maintaining power have been so important that it justified all means and led to the abandonment of the most elementary moral principles? The answer must be that it was the only way for Lenin to put his ideas into practice and “build socialism.” The real motivation for the terror thus becomes apparent: it stemmed from Leninist ideology and the utopian will to apply to society a doctrine totally out of step with reality.
“In that respect, one may well ask exactly how much pre-1914 Marxism there was to be found in pre-1914 or post-1917 Leninism. Lenin of course used a number of Marxist axioms as the basis for his theories, including the class struggle, the necessity of violence in history, and the importance of the proletariat as the class that brought meaning to history. But in 1902, in his famous address What is to be Done? He proposed a new conception of a revolutionary party made up of professionals linked in an underground structure of almost military discipline. For this purpose, he adopted and further developed Nechaev’s model [see note below] which was quite different from the great socialist organizations in Germany, England, and France.
In 1914 Lenin made a definitive break with the Second International. At the moment when almost all socialist parties, brutally confronted with the power of nationalist sentiments, rallied around their respective governments, Lenin set off on an almost purely theoretical path, prophesying the “transformation of the imperialist war into civil war.” Cold reason led him to conclude that the socialist movement was not yet powerful enough to counter nationalism, and that after the inevitable war he would be called on to regroup his forces to prevent a return to warfare. This belief was an act of faith, a gamble that raised the stakes of the game to all or nothing. For two years his prophecy seemed sterile and empty, until suddenly it came true and Russia entered a revolutionary phase. Lenin was sure that the events of this period were the confirmation of all his beliefs. Nechaev’s voluntarism seemed to have prevailed over Marxist determinism.
“If the prediction that power was there to be seized was correct, the idea that Russia was ready to plunge into socialism, making progress at lightning speed, was radically wrong. And this was one of the most profound causes of the terror, the gap between a Russia that wanted more than anything to be free and Lenin’s desire for absolute power to apply an experimental doctrine.” (p. 737-738)
[note: Nechaev] "Throughout the nineteenth century one section of this revolutionary movement [the Russian Land Movement] was linked to violent activity. The most radical proponent of violence within the movement was Sergei Nechaev, whom Dostoevsky used as a model for the revolutionary protagonist of The Devils. In 1869 Nechaev published a Revolutionary Catechism in which he defined a revolutionary as:
“A man who is already lost. He has no particular interest, no private business, no feelings, no personal attachments, and no property; he does not even have a name. Everything in him is absorbed by one interest to the exclusion of all others, by a single thought, a single passion…revolution. In the depths of his being, not simply in words but in his actions as well, he has broken all links with society and the world of civilization, with its laws and conventions, with its social etiquette and its moral code. The revolutionary is an implacable enemy, and he carries on living only so that he can ensure the destruction of society." (p. 730)