1st is that having a successful war of naked conquest is a very dangerous precedent to have. If this is normalized, then we're going to see a lot more armed conflict. I've seen people here claim all sorts of justifications for Russia's actions, but Putin himself in the announcement for the "special military operation" was waxing nostalgic about the Russian empire of Catherine the Great. He's been relatively clear in his statements what he's doing and why. He wants to build a new "Ruskiy Mir", where whether you want it or not, Slavic peoples will be absorbed.

This already had precedent when the US invaded Iraq amidst near global condemnation and more or less took Iraq's entire gold reserve like some marauding army sacking an ancient city.

2nd is nuclear proliferation. Ukraine gave up it's nukes for security guarantees from the US and Russia. This sets the precedent that the only way to be truly safe from wars of aggression is to have nukes and threaten your neighbours with them.

This also had precedent when NATO invaded Libya, which then prompted the DPRK to nuke up. That's reality. You're a lot more safe from invasions if you have nukes.

In general, your points only make sense if you're focusing exclusively on Europe and ignore the rest of the world.