And do we know for certain that Biden didn't want to do the no fly OR that hose countries that might bear the brunt of a Russian response, Germany, France, UK, Norway, Sweden, Romania and the Baltic states said don't do it?
How about the Joint Chiefs? We'll have to wait for the aftermath to find out who advised what, for and against.
There's no unilateral NATO response in a European war when the one with the most capability to do such is not a target for tactical nukes.