The EU is dependent on RU energy exports. It's that simple.

Noble principles do not heat homes, or feed the hungry.

You are free to construct a dichotomy of tanks rumbling over homes, or homes being deprived of heating during hard winter.... but you will only succeed in illustrating the Nash Equilibrium, and fail to be persuasive otherwise.

Try to look at the big picture.

Europe being dependent on Russia for energy is not a cosmological constant, but a result of multiple political decisions done over decades that are being _slowly_ reconsidered now (nobody is closing the first Nord Stream yet for one)

I’m not sure how this illustrates Nash Equilibrium, nothing stable about this. This is just a hegemonic but declining power (USA), that provided security and stability assurances, which is no longer able to provide those assurances. Putin sees an opportunity to rebuild glory of Russian empire and distract from crushing domestic issues.