>The problem is the precedent that sets. Russia launches a nuke on Ukraine, and there are no repercussions. That will teach every nuclear-armed state that they can freely nuke non-nuclear-armed states without consequence. But then what happens when somebody makes a mistake?

I agree with you. It's really bad and it's a slippery slope. It's also true that there are many scenarios where you can launch nukes without repercussions. That's the misperception I'm pointing out.