The Ukrainian Armed Forces was small prior to 2014 but they grew it substantially after Russia snapped up Crimea and sent the little green men to fight them in the east which is part of why they were much more prepared for the renewed invasion efforts than they had been eight years prior. This is not to say that Russia stands a chance against NATO but it is to say that Ukraine presently has a very large and powerful army even compared to leading European powers at this point. Zelensky said France presently has about 200k men in the military while Ukraine had at that time some 980k men in the military, and Ukraine are spending many tens of billions of dollars on the military also.

People keep thinking Russia would attack in order to conquer and occupy Europe for some reason. I doubt that would be the plan.

Russian economy is focused on weapon production now. Changing this focus would take time and cost a lot of money. Instead of doing that they can keep manufacturing weapons and send couple hundred thousand of their people to die in another war. Any direct attack on EU member would most likely send the entire block into recession. China could buy a lot of oil from Russia and help their economy in other ways in exchange for that favor.

Basically the fear is that another war is the easiest and best way to keep Russian economy running. The only cost would be more dead Russians and Putin doesn’t care about those.