The word 'Communist' has changed its meaning since Marx and Engels wrote the Communist Manifesto over 150 years ago. The word 'Communist' is usually associated with the regimes that took that name, such as those that ruled the former Soviet Union and its East European satellites. Although capitalism and feudal landlordism were abolished in those countries, those "Communist" regimes represented a grotesque caricature of the genuine ideas of the Communist Manifesto, and were a collection of ruthless dictatorships based on bureaucratically planned economies.
Lenin and Trotsky, the leaders of the Russian Revolution of October 1917, always explained that socialism "requires the joint efforts of workers in a number of advanced countries," (as Lenin repeatedly put it) meaning, in particular, Western Europe. Both economically and politically Russia was a relatively backward, overwhelmingly peasant-based feudal society. It was not an advanced capitalist economy, where the processes described in the Manifesto were preparing the ground for a successful transformation into a socialist society. Genuine socialism could not grow on its soil.
In the 1882 Preface to the Russian Edition of the Communist Manifesto, Marx and Engels acknowledged that (at that time) more than half the land of Russia was "owned in common by the peasants." Was Russia fated to emulate the West and go through a capitalist development before it could turn to socialism?
The idea that the Russian Revolution could jump over the need for a long capitalist development and move straight to socialism, only so long as such a revolution become a signal for a proletarian revolution in the West, where conditions for socialist development were maturing - a European revolution which could in turn then provide a basis of support for the Russian revolution - this was the outlook of Lenin and Trotsky.
This was not day dreaming. The Russian Revolution of 1917 inspired revolutions and uprisings throughout Europe, including in Germany in 1918, 1919 and 1923. But with poor leadership, they failed to overthrow capitalism. As explained in What About Russia? on this site, the continued isolation of the Russian revolution in the economically backward territories of the Soviet Union led to the inevitable destruction or degeneration of the genuine socialist ideals of the Russian revolution. The leaders of the Bolshevik Party at the time of the Russian Revolution all stated that:
Capitalism and Landlordism was subsequently overthrown in several other countries throughout the world, such as China and Cuba. But these countries were also mainly peasant based, and established regimes following the model of the Soviet Union under Stalin. None of the regimes which are called Communist represent the true aspirations of the Communist Manifesto.
In the Preface to the English edition of the Manifesto of 1888, Engels explains that when the Manifesto was first published, the word 'socialist' referred to utopians and quacks, whereas those workers who wanted "a total social change," called themselves "Communists". But by the time Engels wrote the preface to the German edition of 1872, he could declare that the Manifesto had become an "historical document which we have no right to alter."