> There's nothing to be gained by allowing one corrupt regime to battle another corrupt regime

This is the least ambiguous war you're ever likely to see. There is clear right and there is clear wrong.

Ukraine is clearly in the right. Russia is clearly in the wrong.

Submission to the aggression of an authoritarian regime that has invaded your nation is the dumbest, most nihilistic, most futureless choice available.

It's not rational to choose it.