> I saw very few regime collapses unless an army steps into the capital. That's not going to happen to Russia (Mutual Assured Destruction.)

The reference to MAD makes sense only in the context of foreign armies (and with the M only those of major nuclear powers), but if you look at the two immediate predecessors of the modern Russian Federation (the USSR and the Russian Empire), both fell without a foreign army entering the capital, and are hardly unique in history in doing so. And to the extent status as a major nuclear power is relevant to that, the USSR had it just as much as the Russian Federation does.