People keep bringing WW3 up but I disagree. There's such a huge aversion in EU countries against any kind of war against Russia and the governments know it. They will let a LOT slide on Russia's side before any kind of retaliation (and I mean by force) is coming. Russia could probably kill several service members with a drone, claim it was an accident and the only thing coming from Europe would be a stern letter, some more sanctions and telling off the ambassador (and the Kremlin knows this too).