Two thoughts come to mind:
1) The West has already weaponized the law. It is currently operating on the Latin American dictator model of "for my friends, anything; for my enemies: the law!".
2) The United States strongly opposes the ICC treaty and does not accept its jurisdiction overs its nationals and is even willing to use military force to free any of its nationals should the ICC ever try to enforce jurisdiction over an American[1]. In similar, but less violent terms, Russia withdrew from the ICC back in 2016.
So my point is, why would Russia care what some court with no jurisdiction says? It's already obvious it won't matter. The West is already going full Treaty of Versailles on them - so what difference does it make? There is little credibility left for the West, either in terms of rule of law or moral authority to be telling anyone what is right or wrong.
This is something that most of the world sees by now, but the West is comically unable to look in the mirror and see this and I'm afraid they will only notice when it's too late. It's absurdly self-destructive but the West consider it "winning", yet the history books will almost certainly mark this as the most obvious inflection point where the West lost the plot.
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[1] https://en.wikipedia.org/wiki/International_Criminal_Court#C...