Interesting piece, the central thrust of which I agree with: That the EU needs to organise its own defence and to take it seriously. As the largest economic bloc, there is no excuse for it lacking the resources to mount its own defence.
One observation: The size of the Ukrainian population is about one-third that of Russia's. If supplied with weaponry by the rest of Europe and organised on a militia basis similar to that of Switzerland, it should easily be capable of fielding a force greater than one-third that of Russia's. From what I hear there is no lack of readiness to fight on the part of Ukrainians. Crimea, moreover, has a land-bridge to the rest of Ukraine more substantial than its connection with Russia. It could be taken back and held if the will of Europe were united behind the venture.
A defence that does not include delivery of ordnance deep within Russia is no defence at all, however. Russia has rocket artillery with ranges in the hundreds of kilometres, delivery systems of all ranges up to and including global and an air-force which is actually launched and provisioned from bases within Russia. Allowing it to fight only on European soil, pounding us from behind the Urals, makes war a cost-free proposition for Russia. Not only must its assets be destroyed where they are based in order to defeat it but it must know that its doctrine of tactical nuclear use will trigger an annihilating response: Europe needs a modern nuclear force of its own based close enough to Russian cities that its leadership know they are personally not immune.
We live in a world of rocketry, drones and robotics. I knew in the 1980s of British anti-radar missile systems that can loiter over the battlefield and eliminate radar antennae as they are switched on. There's been four decades of progress since then. The USA has weapons that can dispense 200 individually-targetted anti-tank munitions from one automated vehicle, and Russia has supersonic torpedoes. Armoured columns, bombers and ships are just big, fat targets in a world of terminally-guided sniper's bullets and autonomous drones. Individual soldiers little more so.
A fully-modern European defence force could make its Eastern frontier unassailable. What has been lacking is the will.