what was the class character of the Soviet Union?

[Hnv1]

Whilst growing up we analysed the USSR collapse and the reasons for it (as I previously states I grew up in a MAPAM home, it was the Marxist party of Israel).
The bottom line of the analysis and the reason for the collapsed were already outlined in our party convention of 1968: the combination of state capitalism with a bureaucratic mechanism that choked true socialist efforts, with the going continuation of the dictatorship of the proletarian,  the democratic socialist phase was just evaporated from soviet planning (against original Leninist plans) .