The West has been lulled in a false sense of security over this and both the people and their governments have been spoiled by winning easy wars against inferior 3rd World militaries. The prospect of going up against an equal enemy has got a lot of people scared and many will be unwilling to sacrifice a lot of lives to defend Ukraine.
The Ukrainians are also partly to blame for believing the rhetoric that there will be other nations that could help in in situations like these. I think other countries iwll now realize that if faced with war against a regional power the US will ultimately back off from their assurances and treaty obligations. In the end, nations cannot depend on others for their defense and the Ukrainians should not have given up their nukes- at one time their nuclear forces were larger than UK, France and China's combined but they gave it all up- and now its going to cost them.
As an anecdote, I was in Estonia when the Russians invaded parts of Georgia and every single male citizen of that country got a letter from the government saying that they needed to be ready to be called up for active duty. The former Eastern bloc countries take incidents like this very seriously and there will no doubt be a new arms race in the region regardless of the outcome.