What failsafes are in place for a future government which tries to exploit the powers

At first - This is just a question about how its done in Poland. This no critique or whatever else especially because I have no idea about the polish specifics.

For the context - I'm german and currently I'm a bit worried that the (our) government gets more and more power over everything over the past years and its ongoing (surveillance of the regular people, military and so on). Of course all for the "we need more security, our people feel unsafe". I guess we all notice the rise of the right power accross europe (France, Italy, Germany of course...) so none knows who might be in charge in 5...10.... years . Instead of strengthen the sovereignty of its population and the democracy (division of powers) I notice the urge of every current and past administrations to weaken it for "making it easier".

Imagine a pro-russian or far-right gov. gets in charge in the future with all failsafes removed which where added in our all socities (I guess) after WW2 - wouldn't that be bad?

What failsafes does Poland have? Image a pro-russian leader gets elected (I guess everyone now would agree that this would never happen in the forseeable future) would he have "full access" to the military for example? How is the seperation of powers handled in Poland? I guess they would have to replace judges in the high court as well as some military generals so they can completly rule? Or are there other things in place which would make it hard?

For example: In Germany, 2/3 of the German Bundestag have to agree that the state of defence is reached and the military gets deployed. In case of the requirement of immediate action because of an emergency - this process can be shortened of course.
Germany attacking another country is forbidden by the UN Charta which applies for every UN country (Russia itself didn't care...) and by germans Code of Crimes agains International Law (punishable by lifelong imprisonment). I don't know what majority is needed to change this law.....

But maybe this is all just too theoretical because laws are one thing - what if a government just ignores them (see Trump...) and the prosecution is "too slow" before they created facts.

What are your opinions on that?