enforcing a no fly zone = killing russian pilots and planes.
if we are going to kill russian pilots and planes, we are entering full scale warfare with Russia - as is the rest of the world no matter if they want to or not. if we are going to do that why the hell would we "just" enforce a no fly zone?
yes, thousands of Ukrainians will die needlessly. while it is unfortunate as hell, they are not part of NATO (and only 54% of UKR people want to join pre this fight), they are not part of the EU - only 58% of people wanted to joint that. 21% of people wanted to join a customs union with RUS+Belarus+Kazakhstan. there is no clear want by the UKR people over time to join either group and ally themselves to Europe or NATO. they JUST requested to join and have their request fast tracked THREE days ago.
this isn't going to fight against Iraq or the Taliban, this is a full hot war against a nominal superpower with nukes. you don't jump into that kind of war over someone who isn't an ally, someone who hasn't joined your alliance and someone who had limited interest in pushing to join the alliance until they were invaded.
going balls to the wall into a nuclear war with the rest of the world against fucking Russia over a country that has had every single opportunity to lean closer to Europe/NATO and has opted not to over the last 30 (!!!) years seems like an iffy choice when there are so many other options.
~250k people have died in the Civil War in Yemen and nobody was interested. somewhere between ~120k and ~150k from 06 to 18 died in the Mexican Drug War. Est 350k have died in the Boko Haram/Islamist fight in Nigeria. ~350k have died in the Syrian Civil War.
don't see you or most others pushing to enter any of those conflicts, which are worse in basically every way for humanity as a whole when it comes to how many folks it has impacted, just because the fucking Ruskies are not on the other side.