To wear down Russia to manageable size: get the Ukrainians to pay in blood and the EU to pay for the bombs. Bonus: Germany crippled because cut off cheap gas supplies, and prevents Russia Germany alliance turning into rival superpower to USA. Another bonus is EU crippled with war debt.

This war is about geopolitics. Not morals or ethics. The USA wanted this war to wear down Russian power. Putin took the bait.

Who scuttled the early attempt at a peace deal? Boris Johnson, on behalf of USA. Because the USA wanted this war.

But now Russia and China are allies. That's a bad geopolitical outcome for USA.