That angle exists, but Russia’s situation is different from what the US did with Iraq — the US lied about Iraq soon gaining the capability to strike the US with missiles and WMDs. And it claimed a valid casus belli to declare war. Both were lies. So their casus belli is invalid.
In contrast, Ukraine had been tolerating or had been unable to rein in the Nazis that plague their establishment. Moreover, on top of already having openly declared that they were going to ethnically cleanse Russians, those Nazis were already murdering Russian dual-citizens in Southeast Ukraine. This not only creates a valid casus belli per actual international law, but also constitutes a crime against humanity.
People think that you cant declare war against a nation before being attacked. They are wrong. International law allows declaration of war in such cases.
As a sidenote, Nazi problem in Ukraine has long reached a level that is way over the Ukrainian government’s capabilities to handle.
At the moment a group of armed, organized extremists can publicly threaten with death the president of a country in public social media and get him to do what they want, is the moment at which any claim to democratic authority stops.
