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?
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?