> But here is what I find amazing: we have already seen this movie and we know what forces are at play and what the likely outcome is. Namely, it is very difficult to maintain legitimacy as a government through a propaganda campaign. It is a highly unstable equilibrium. At any time, information can get out of the hands of the propagandists and the system will find a more stable equilibrium -- ie. leaders will be replaced. It's just a matter of time.
I'm not sure I believe this. I used to, but Russia is the perfect example of revolutionary change resulting in more of the same. Leaders are replaced, but the power machine of the USSR is alive and well. The Communist party may have abandoned communism, but they kept the bureaucracy and corruption.
Russian leaders since Ivan the Terrible have known that projecting power outward is the only way to protect the western front. Geography is both Russia's best friend and biggest enemy. Moscow is situated in the middle of a wide, flat plain, which makes marching an army there logistically trivial. So Russia's national security has always relied on maintaining a large buffer zone around Moscow, and relying on the distance combined with Russia's harsh winters to destroy its enemies. If an enemy could stage an army and extend supply lines into Eastern Ukraine or the mountains in Georgia, a ground invasion of Moscow would be relatively easy. It's no accident that Russia is occupying both of these areas after their governments started to distance themselves from Moscow.
This is further exacerbated by the fact that Russia is quite literally frozen out of internationally commerce. Russia's major ports (with the exception of Kaliningrad, which is separated from the Russian mainland by Lithuania and some ports in Siberia that are too far from Moscow to matter) freeze over completely in the winter. This makes it very difficult for Russia to be a strong naval power outside of their submarine fleet (which can just go under the ice). The result is that Russia sees its outward expansion as a national security imperative -- so the saber-rattling isn't just for show. If Russia were to join the NATO / EU system, they lack the economy to be more than a #4 player (behind France, Germany and the UK) in the EU despite their large population. They look at Ukraine and think "If we were able to invade Ukraine and NATO did nothing, they would not come to our aid either if we were a member." Thus, Russia pursues a policy of self-determination.
And to address your point about the release valves of the "stable" systems, I'm not sure that applies to Russian psychology right now. The Russian people can rightly say "We've tried both of those systems, and they were both awful." There's a movement among the Russian masses that thinks while things weren't great under the USSR, they were better than they are today. I'm not stereotyping all Russians as thinking this; but it's a sizable movement similar to the Tea Party (or whatever they call themselves now).
And because Russia has the veneer of democracy, Putin doesn't have to even win over the entire populace or fix elections to stay in power. He can have his core bloc of corrupt politicians that support his economic policies (and who stay in power through good old American-style political machinery in the major cities), and shift his social policies to match whatever the most popular social movement of the day exists. Putin makes a powerful friend and an even more powerful enemy, so those groups are more than happy to ally with him when it suits his needs.
I think you're right about it being inherently unstable; but as long as Putin is alive it will stay together. If he's smart and not completely insane, we'll see him start publicly grooming a successor in the next few years. If his successor is as politically savvy as Putin, Russia could be a pain in everyone's ass well into the mid-century.