The problem with the appeasement argument is that we're not talking about 1939 Germany. We're talking about Russia, the country with the largest nuclear arsenal on EArth (yes, even larger than the US nuclear arsenal). The analogy isn't remotely similar or appropriate.
Let me put it another way: what is the alternative? We're clearly not going to put boots on the ground. NATO does not want a member country directly on the Russian border, particularly a large border as Ukraine and Russia have. The US (and the rest of NATO for that matter) simply does not want to get dragged into a conflict on Russia's borders. That's it.
The US would never accept a military alliance between Russia or China with Mexico and Canada that allows Russia or China to build military bases along the US border. So why should we be surprised that the "F** the USSR" military alliance may end up building bases on Russia's borders?
I should probably say a significant border with Russia. Norway's border with Russia for example is a narrow sliver of mountains. It's completely insignificant. Finland isn't part of this because they're not a NATO member. The Baltic states (Latvia and Estonia; Lithuania doesn't obrder Russia) are a little more nuanced. I imagine that was a tough pill for Russia to swallow but again the borders are small. Poland and Kaliningrad is also more of a technaclity.
This map [1] puts the size of the borders in perspective and also why Russia has made Belarus effectively a client state. And also why Georgia is in a similar position as a buffer between Russia and Turkey.
But Ukraine is of particular strategic importance to Russia not only because of the expansive border but because Ukraine is relatively flat. Here's a map of the Operation Barbarossa invasion route [2]. It was largely through what is now Belarus to the north and Ukraine to the south.
I can't find a similar map but I believe Napoleon followed a similar route.
While niether of these two campaigns were successful, quite famously, it's merely a function of geography.
Additionally, Ukraine's position is even more significant because it potentially threaten's Russia's access to the Black Sea and the occupited territory of Crimea.
"Norway's border with Russia for example is a narrow sliver of mountains."
Wrong. It's fairly flat, mostly tundra and swampland.
"Additionally, Ukraine's position is even more significant because it potentially threaten's Russia's access to the Black Sea and the occupited territory of Crimea."
Wrong. Just look at a map.
Given this is already a pivot to sharing a "significant" border with NATO, perhaps you should be a bit more discerning with your statements.
If you really want to be pedantic, the US and Russia have a sea border.
If you count EEZ's, Russia's and Turkey's EEZ border each other in the Black Sea, as would Romania's if you believe Crimea (and hence its associated EEZ) to be part of Russia.
Let me put it another way: what is the alternative? We're clearly not going to put boots on the ground. NATO does not want a member country directly on the Russian border, particularly a large border as Ukraine and Russia have. The US (and the rest of NATO for that matter) simply does not want to get dragged into a conflict on Russia's borders. That's it.
The US would never accept a military alliance between Russia or China with Mexico and Canada that allows Russia or China to build military bases along the US border. So why should we be surprised that the "F** the USSR" military alliance may end up building bases on Russia's borders?