I am not sure Yugoslavia in the 90's qualifies as peace, Ant. Genocide - shove your "ethnic cleansing" you weasel filth - rape, mutilation, and slaughter of innocents, including babies and children under the watchful eye of the UN. Yeah, Europe didn't have a major conflict involving multiple states. But some of those states just shifted the theatre of conflict in that 70 years out of Europe - Congo, Algeria, Korea, Vietnam, Laos, Cambodia, Iraq, Afghanistan, for example.
Nothing can be done is not the message. Something needs to be done. War is a lucrative exercise for some. Bullets, munitions, weapons, equipment. Some executives and shareholders will be receiving a financial boon from the tissue shredded and the blood spilled in Ukraine. And they will toast their profit with excess as they always do. And then when this war is consigned to a simple wiki page they will plot and scheme their next sales push in the halls and corridors of capital buildings around the planet. And another war will occur somewhere around the globe. My money is on Taiwan.
Putin needs to be hung. That's what needs to be done.