Why are European nations concerned about their security in relation to Russia and Ukraine?

European nations are legitimately concerned about their security because Russia now poses a real and imminent threat of attack. Dr. Malcolm Davis explains that this worry extends to Ukraine's situation, as European leaders understand the strategic implications of Russia's potential victory there. If Russia were to win in Ukraine, especially if the West cedes Ukraine to meet Putin's demands, it would reinforce the prospect of a wider regional war. This outcome would significantly increase security risks for European nations, validating their current apprehensions and necessitating stronger defensive postures across the continent.