Even Max Boot realizes  that shooting down Russian jets over Syria is too reckless to be tried, so he goes looking for some other war that the U.S. can make worse:
Supplying arms to the Ukrainians will increase the pain of Putin’s Ukrainian offensive and divert his attention away from Syria.
It seems to have escaped the notice of hawks here in the U.S., but the cease-fire in Ukraine has largely been holding  for many weeks, so their demand that the U.S. send arms to Ukraine is even more irresponsible than it was when they first started making it. Arming Ukraine was a lousy idea when the fighting was still going on, but now that there is a better chance to secure peace it is even worse.
Supposing that the administration were stupid enough to do as Boot recommends, it would only be able to divert Russian attention away from Syria if it led to a new Ukrainian offensive to inflict more “pain” on Moscow (i.e., kill more Russians and their proxies). That would in turn ensure that the conflict in Ukraine worsens to the much greater detriment of Ukraine. To the extent that arming Ukraine “succeeds” in doing this, it would mean that many more Ukrainians would be killed for the sake of distracting Russia from its latest misadventure. It’s not clear how anyone would benefit from this, and it would force Ukraine to endure additional losses for no good reason. It’s also possible that arming Ukraine wouldn’t have the desired effect, and might instead encourage Russia to become more combative and intransigent across the board. Except for perversely wishing to prolong and stoke a conflict that has been dying down, it is hard to see why anyone would now support such a measure.
The impulse to counter every Russian move with an opposing move is a common one among Western hawks, but especially in Ukraine and Syria it makes no sense. There is no particular reason why the U.S. needs to counter Russia’s intervention in Syria, and none of the proposed counter-moves serves American interests. In fact, the automatic reflex to seek to counter Russia allows Moscow to have more influence over our policies than it otherwise would. Mark Galeotti made  this point very well recently when he said this:
The fundamental point is this: The more the West lets itself be shocked into responses by Putin, the more power it gives him, the more reason he has to continue to goad and needle.