With comming sanctions those people will suffer, Putin and his inner circle doing all they can to stop the protests.
Mongols, Tatars, Vikings, Teutonic knights, United Europe under Napoleon's France, United Europe under Hitler's Germany, and now United Europe under Anglo-American Empire. Russia is under sanctions for the last 1000 years. They simply do not care about sanctions when they have to defend their country.
Conclusion:
There can not be security for the Brussels Union if there is no security for the Russian Federation. If you say that you don't care about Russian red lines you just get kicked in the backside.
Ukraine lost their sovereignty in 2014 and became Anglo-American colony under Nazi rule. Putin just gives Ukraine a second chance to have a truly independent, neutral and democratic country.
Meh, we've already been through this in the 60s, MAD
https://en.wikipedia.org/wiki/Mutual_assured_destruction that's the only thing guaranteeing security on this blue marble. When Soviets got too close to US through Cuba, US made Cuba a failed state. Now it seems US got too close to Russia through Ukraine, and Russia is about to make Ukraine a failed state. Sucks for the people, war is hell, but these proxy wars are better than the alternative of direct confrontation.