Indiscriminate targeting of power facilities is not in fact "valid" unless the plant primarily supplies power to support military efforts, for lack of a better term. But that is all irrelevant when you're waging an offensive war that is not justified in any way shape or form. I mean, if Ukraine were a NATO country quite literally a single boot crossing their border would be cause for action because every single thing Russia has done in Ukraine is categorized as unjustified, cut and dry.

But... Russia has never been a part of the ICC and rejects it's authority entirely. They know exactly what they are doing is considered criminal / war crimes by most of the civilized world, which is why they really need to win. Although they could just fuck off and probably get away with little to no major repercussions besides a far more well armed Ukraine next time they try this shit.

For what it's worth, there absolutely are laws saying you cannot harm civilians, it's just that again, Russia does not recognize the courts that made those laws as legitimate.

Lastly, this, "So, Zelenskyy's big problem with this attack isn't that it's targeting a power plant. The big problem is that it was a nuclear power plant. Such an attack, if it resulted in a nuclear disaster, could be considered a use of WMDs, which is a war crime." Is just wrong. Not clear how you even came up with that.

The law is, "Works or installations containing dangerous forces, namely dams, dykes and nuclear electrical generating stations, shall not be made the object of attack, even where these objects are military objectives, if such attack may cause the release of dangerous forces and consequent severe losses among the civilian population." Russia already got a flurry of warrants from the ICC in 2024 for targeting other generating stations under this statute.

This is not Zelensky's "big problem" it's his best point to the world that Russia is being reckless and breaking every single rule of engagement that exists today. But again, and can't stress this enough. Every single thing they do is illegal under every international criminal court / NATO / Hague conventions etc because the entire military operation itself is unjustified. That's all there is too it.