History of the Soviet Union (1964–82) Brezhnev remained wary of any sort of intervention and Kosygin reminded leaders of the consequences of the Soviet suppression of the 1956 Hungarian revolution. In the aftermath of the invasion the Brezhnev Doctrine was introduced; it stated that the Soviet Union had the right to intervene in any socialist country on the road to communism which was deviating from the communist norm of development. The doctrine was condemned by Romania, Albania and Yugoslavia. As a result, the worldwide communist movement became poly-centric, meaning that the Soviet Union lost its role as 'leader' of the world communist movement. In the aftermath
Railway electrification in the Soviet Union on electrification investment (to replace diesel traction). By 1990, the electrification was about half 3 kV DC and half 25 kV AC 50 Hz and 70% of rail passenger-km was by electric railways. Compared to the US, the Soviet Union got off to a very slow start in electrification but later greatly surpassed the US. Electrification in the US reached its maximum of 5,000 km in the late 1930s which is just when electrification was getting its start in the USSR. About 20 years after the 1991 demise of the Soviet Union, China became the new world leader in rail