Biden is just trying to look though. I don't think he has any interest in a direct confrontation with Russia.
Exactly, it's just posturing. Russia in the Ukraine and China in Taiwan are both testing the new president out, seeing how far they can push him. There is no appetite for direct conflict between superpowers, or an expensive foreign war.
The Russia/China parallels are quite striking, their strongman attitudes, the way they present their respective annexations as 'internal' matters. But it's a balancing act, they both know they can't push
too far... it's just a matter of determining what they can get away with... which I would imagine is quite a lot.