I think the thing is that the formal and informal structures need to be somewhat in alignment. A lot of countries have the form of institutions, but not the deep-rooted culture.
In theory the British Parliament could collectively lose its marbles and transform the UK into a totalitarian state in the space of a few weeks. In practice it's very unlikely to happen. The informal and formal are closely aligned in the political culture.
In theory Russia has the separation of powers and independent media. In practice, it doesn't. The informal and formal are misaligned, which in some ways is worse than never having the formal stuff in the first place.
Actually, during the Cold War there were fairly detailed plans the, if executed, would have turned the UK into a totalitarian state pretty quickly - Duncan Campbell exposed these in his excellent series "Secret Society" - and particularly the episode "In Time Of Crisis: Government Emergency Powers"
The fact that these plans existed during the Cold War is not really a surprise (although the severity of the planned measures is quite alarming - no wonder they tried to keep them secret).
What I do wonder about is what state these plans are in now and under what circumstances they could be used.
In theory the British Parliament could collectively lose its marbles and transform the UK into a totalitarian state in the space of a few weeks. In practice it's very unlikely to happen. The informal and formal are closely aligned in the political culture.
In theory Russia has the separation of powers and independent media. In practice, it doesn't. The informal and formal are misaligned, which in some ways is worse than never having the formal stuff in the first place.