The Russian invasion can be seen as interfering with one side in a civil war that is historically a part of their country and has little to do with the Ukraine, and it does not have many parallels to WWII, IMO... I think each conflict has to be treated differently.

Hitler also saw Danzig as part of Germany and used that as pretext to invade Poland. Eastern Ukraine is not more Russian than Danzig is German. The Ukrainian borders were already agreed upon after the fall of Soviet Union.

Here we are at the point where left wing progressives talk about how world peace has been maintained by the UN charter forgetting by the millions dead in Vietnam and Iraq at the hands of the US who blatantly could ignore these things.

I concede on Iraq. Though on Vietnam, the US involvement is at the invitation of South Vietnam. US also did not invade North Vietnam. Same as Soviet Union was in Afghanistan. USSR did not invade but was invited by the ruling Afghan communist government.

Moreover, just because another country acted with impunity doesn't mean another could. Tell me you support imperialism without saying you do simply because others did.

Edit: Lastly, allowing Russia to get away with this sends signal to China to also invade Taiwan, and beyond.

I will not argue with someone who wants to believe that Biden has the right idea on this, but political pressure keeps him in the game of supporting a war abroad.

He still has to appease subordinates, peers and electorates. It's ill-informed to think he is immune to political pressure, especially in a democracy. Leaders, even dictators, rarely have absolute power.

This can be seen as part of my thesis: someone like Trump who is not beholden to the system has more ability to break from foreign policy norms.

Breaking norms such as stealing classified documents, especially relating to Russia? I suppose you don't mind breaking foreign policy norms that support Russia?

Ukraine is already a lost cause - the most recent declaration appears to make it so that Ukrainian women will now be drafted and sent to the front alongside their men since they are so starving for soldiers. It's unprecedented.

Ukraine already have women in the armed forces anyhow. And it is not like this makes any difference to Ukraine who is already in a total war. Russia, on the other hand, is suffering massive demographic crisis and labour shortage even with partial mobilisation. Putin will call upon more soldiers. The cost of war is creeping into the Russian society, which Putin had been trying to avoid but it will eventually come full circle.