Answer:
From 1919 to 1923 a tremendous revolutionary wave struck capitalist Europe. Europe barely survived as a capitalist territory. Since then revolution and near revolution have shaken country after country from China and India to England and Germany. War, revolution, crisis, these things show that capitalism is doomed; only the process by which the workers conquer is not a simple or a single act. It is a long-drawn-out one. Therefore since the capitalists are not overthrown all over the world with one stroke, since they use their state machines, their armies, and navies desperately to maintain their property and their power, the workers too are organized into a state to crush and conquer the capitalist states. It is quite natural, therefore, that Russia, still isolated and alone as a socialistic state, should not have an easy time of it.
When, however, the workers of the world unite to take over power and to smash the capitalist regimes, then the rule over persons will begin to give way to an administration over things. The state, with its religion, will begin to wither away. There will be no exploitation. There will be no classes. Each will receive according to what he puts in, and as the productivity of labor will greatly increase, each will receive according to his needs and will contribute according to his ability.
When we have reached Communism we will have done away with both the Social Order and Social Disorder and humanity will have reached a rational system of society where development of mankind will no longer be choked by social relations, where, therefore, society will be a free one and man emancipated.
A Communist looks upon the social order not as stationary but as constantly in evolution and he looks at the evolutionary process not as a smooth unilateral one, but at any given moment, as the unity of contradictory forces. Close to the scene of struggle we see the noise, the conflict, the violence. Only from a more profound perspective can we see that it is the very series of clashes and revolutions that go to make up the evolutionary process itself. From this point of view, there is no sharp line between evolution and revolution. Evolution prepares the way for revolution; revolution is only a part of the grand historical spiral evolutionary process. Hope it helps.