Hot Cyberwar Russia vs. USA – EU. Risks?

I was discussing the situation as it is now, in "peacetime" earlier today

I described our current gentle, peaceful, mode of life as

    "cybersecurity as it is now is... intense, it's a war zone, where your fortifications are made out of crates of nitroglycerine
    any computer can be hacked, that then becomes a gateway to all the other computers
    it really frosts my cookie that this was SOLVED back in the 1970s, but everyone forgot the solution"

Every three letter agency in the world has been buying up and stacking zero days for decades. If they get used, and ZERO bullets fly, it could still kill millions of people.

Think I'm being hyperbolic with that estimate? Consider the supply chain chaos when everyone was working together, trying to get you toilet paper. That could ramp up x100 for everything, money, fuel, food, medicine, power, pipelines, etc.

If people actually start taking things out, a lot of people are going to have to figure out how to re-image their systems and restore from last month's backup, then delta forward.

The only possible action in the case of a hot cyber war for a small cyber player is to sit on the ground, put their head between their knees, and kiss their ass goodbye. Even if you have the best security, you leave in an interdependent world and you can bet that significant part of your connections (dependencies or dependants) are vulnerable which will make your stance irrelevant.

The US has been tip-toeing around the idea of responding to a cyber attack with a kinetic response.

Depending on the nature and impact of an attack, I believe it could provoke proportional kinetic response.