The state is the instrument by which a class exercises public political power over another class and society generally in the struggle for control of economic life. An economy is characterised by the predominant mode of production, which in general, changes only slowly. State power, in general, passes from one class to another suddenly, by means of civil war. State power passed to the working class in Russia on November 5 1917. Commodity production was not abolished until the mid-1930s, and even then, the social norms were predominantly bourgeois.
Capitalism is the economic system in which the commodity relation becomes all pervasive.
The commodity relation can be found in any society barring the most isolated tribespeople or the far distant future socialist society. Indeed wage payment is only truly such where there is both a real labour market, and free labourers offering labour power for sale. Payment of cash wages to slaves does not stop them being slaves. Capitalism has existed in the Soviet Union since the War only on the margins, but has grown with the expansion of the black market, drug trade etc, and foreign trade. This does not mean that socialism existed.