Here's the reason in my view this is a difficult situation. On one hand, it's true that Ukraine is not in NATO. That said, we do have to look at history. With a lot of tyrants like Putin, Stalin, and Hitler, the invasions into countries like Ukraine or Czechoslovakia were not where the invasions stopped. Yes, there were things we could've done differently. For example, after WW1, it probably was a bad idea to punish Germany as hard as the Allies.did. That set financial issues on Germany that the collapse of the Stock Market in 1929 exacerbated. This was one of the biggest reasons that Hitler was able to rise to power. It wasn't until he invaded Poland that really started WW2.
Similarly, the ineptitude of Czar Nicolas was a big reason that the Bolsheviks under Lenin and Stalin were able to rise to power. We saw what that led to with the massive growth of the USSR.
Similarly, sure, the west could've been less harsh on Russia to an extent. Perhaps allowing more discussion with Russia could have helped. That said, now that Putin has started on Ukraine, that does not mean he's going to stop there. Look how he's already threatening Finland and Sweden now. In my mind, if he's able to take Ukraine, he's not going to stop there. Why would he? He wants the USSR back. If we compare the Putin invasion with Hitler's invasions, what's to say he won't go after Estonia or Lithuania? They're NATO countries, but, if we don't show more strength to Putin, which is what he understands, and follow the lead of Ukraine, then we might see him continue his conquest until he hits one of our NATO allies until we are forced to defend such allies. Additionally, China wants Taiwan. If we continue to show weakness, we may inadvertently greenlight China to attack Taiwan, who the US I think is obligated by treaty to defend. So, this could get very bad.
