The people themselves were not permitted to know too much about the outside world, a cultivated ignorance, so to speak.
The secret police have a stronger cog-diss because they do know how many lies it takes to keep folks out of the know.

I am just finishing the unknown history of Mao, and back then it was calculated to take 500 armed 'security' thugs to suppress 30,000 peasants. Perhaps it was even less thugs in Stasi days.

The success of a totalitarian state in staying in power always rocks on the fulcrum of the ability of the secret police's willingness to go along with the program.
In a way it is the weakest link in the chain. Lose them and it's game over, so there is a vested interest in keeping them sweet. Favours and perks...

Eventually you have Pakistan/Egypt situations, where the military arm attains near-absolute power, swathes of prime land, etc.

When the costs of repression come too high, then change will come, willy nilly.

This is why America is so busy building up a criminally fascistic element in its domestic forces, to prepare for mass riots if the dollar crashes with such a high proportion of the populace armed.

They backed off with Bundy, but if he had been black and/or religious, it would have gone differently.

Bundy was really one of them, so...

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

Yeah, Stasi and KGB failed completely, without any kicking apart from a weak August putsch in Moscow.

This all be less mysterious if the genuine top objective of these secret services (and Gorbachev government) would had been exactly what what happened.