Maybe we can compare it with Czechoslovakia, but the comparison is pretty week. There was a Czech unit resisting the Germans, but the ethnic Ukrainians will defend their country. What they can achieve is creating a threshold to make any military intervention by the Russians expensive. I don't think we will see any military action before and during the Olympic Games.
I would be more worried if I were in any of the Baltic states. The West could implement the economic sanctions now.
I think it is time we called Putin's hand and moved Western troops into Ukraine, see how his nation will react to demands that he stand down his forces or the West will establish a permanent presence there.
The reality is that the West's procrastinating is emboldening both Russia and China and it is time we put up or shut up.