Yep, call putins bluff and send in troops and wax the russian military. All this "o no they're going to escalate" is just giving them more reasons to escalate, because there is no threat of retaliation from NATO/EU.
It's sadly the case that Ukraine's allies would rather pull a slow burn on Russia by proxy to try and get it to collapse from inside rather than stand up to them directly.
There are no happy endings on the table at this point, only the choice of when things will become difficult for Europe.