The idea of the USSR is to travel back in time and kill Albert Einstein. Three rivals are at war with each other in an interesting campaign, where each country will have to develop, build a base, study technologies, extract resources, and then hire units to go to conquer the closest rival. The Soviet Union did not disintegrate at all, so it became easier to prevent WWII.
IN Command & Conquer: Red Alert 3 we have to return the former greatness of the USSR. But at the moment of travel in time, a malfunction occurs, and the machine makes an alternate universe, where the Alliance and the Japanese were also exiled. The leaders of the Soviet Union became disillusioned with world progress, so they decided to go far back in time to save the world from World War II, to renew the greatness of Mother Russia, to make the state invincible in principle, and not in words.
