So, 1953: Russia goes back. Stalin dies. Much woe is had. For a brief period of time, Lavrentiy Beria takes over, but he's a bit too liberal-sounding for their tastes. So what happens? He's arrested, accused of being a spy, and eventually shot down of course. Thanks to that, Nikita Khrushchev gradually comes into power.
Khrushchev is a bit different. He denounces Stalin's methods and all the labor camps first of all. Then he goes promoting competition with the West, not outright hostility, because he "knows Capitalism is doomed to fail anyway". And then he releases a whole bunch of political prisoners. Communists everywhere are shocked.
But his "let's be nice and buddy buddy with all the other countries", kind of starts screwing him over. Sure there's the lovely Warsaw Pact, but everyone's getting kind of iffy. Poland starts rioting in 1956, but aside from eventually getting yet another Communist leader nothing major happens, all's good. Hungary, on the other hand, tries to revolt at the same time, but is brutally crushed by the Red Army.
Back to the Warsaw Pact, formed because Russia was lonely. Also NATO. NATO is a pretty big threat. West Germany is with them, East Germany isn't. People aren't happy because frankly, being Soviet isn't fun. What do they try to do? Escape. Does Russia let them? Not a chance. Soviet control gets way stricter and right down the lovely heart of Berlin they build the Berlin Wall in 1961. No one can pass, families are torn, world goes into an uproar.
1961 also means Sputnik I goes into the air, and it really isn't a satellite at all. Totally. Space Race starts, America beats them to the moon, Khrushchev continues reform.
1962, another fun year, brings the Cuban Missile Crisis. BASICALLY, Cuba and Russia become friends and think it's cool to hide Russia's nuclear weapons in Cuba. The U.S. butts in and is all LOLNO, and the world comes really close to Nuclear Winter. But Crisis is diverted when they both retrieve their missiles from Cuba and Turkey respectively. Hooray.
Khrushchev doesn't remain in power much longer since all that he's been doing [re: all the reform, Berlin Wall, Cuban Missile Crisis, breaking up with China, worsening the economy etc etc] leads many to not being pleased at all. He's expulsed in 1964.
Leonid Brezhnev is the next to come into power and he takes it a little old school. Sure, there's still some changes here and there, but he turns back onto a lot of the more stable policies. He also starts building up the censorship from the public, propaganda, etc etc.
China and Russia break up their commie friendship even more and become super hostile to one another, oh no. Elsewhere, Czechoslovakia tries to reform/revolt/liberate itself. Russia isn't happy about that at all, and with all the Warsaw Pact buddies, crushes that little rebellion effectively.
Of course, now he's paranoid about any of the others leaving so the Brezhnev Doctrine comes into place stating,
"When forces that are hostile to socialism try to turn the development of some socialist country towards capitalism, it becomes not only a problem of the country concerned, but a common problem and concern of all socialist countries."
In simpler words: You try to stop being Soviet and I will crush you with all I have. Nobody gets to leave ever because socialism is the best thing ever and if you don't see it that way, I'll just beat you until you do.
Cue return to Discedo.