USSR leadership was actually overthrown twice. First Yeltsin overtook top leadership from Gorbachev in 1991 (there were some internal shootings by a third group along the way) and formalized dissolution of USSR. Then in 1993 Russian parliament which was mostly communist/socialist at the time went into hot (with more shootings) power struggle with Yeltsin (both Yeltsin and parliament did some very unconstitutional things) and totally lost (some deputies were imprisoned) in the end.
It's true, but not exactly. Truth is that one group of Communists took power from another group of Communists. All current top Russian politicians are either former members of the Party or their children. Nothing close to revolution ever happened. Internal power struggle and nothing more.
I hope that North Korea will go real revolution route and we'll see some active executions of criminals that control the country now
Thank you for this valuable addition that I contemplated including myself. The rhetoric and official ideology changed* vastly but mostly not the people at the top themselves. When the only party around was Communists all the politicians were pretending to be communists. As is in any party at the top of it - only a minority is in it for ideological reasons.
One not great but not the worst scenario that has some possibility of realizing in NK is Chinese style half-way reforms. That is definitely not possible with the Kim alive, but a military junta could potentially slowly steer NK into mostly capitalistic, mostly working (can't happen without healthy international trade and they would have to make concessions to ease trade sanctions) economy while maintaining ideological iron grip (aka concentration camps for dissidents). The positive moment here is that it would still ease eventual reunification with the South.
*That verbal change from the retarded Lenin's Way™ in my opinion led to big real positive shifts. And people who brought with them these changes, however crooked politicians they were, won because they had strong popular support.