Notes:

It didn't work in the 1930s and '40s, and it won't work now. Appeasing (or worse, aiding) dictators like Putin only emboldens them to invade more territories in the future, and a Ukrainian defeat could conceivably result in American troops being deployed in a future war with Russia. Giving Ukraine the aid they need for victory will not only shorten the war and save lives, but also stave off future conflicts by providing a strong deterrent against future Russian aggression.