Europeans spend a much higher proportion of their defense dollars on payroll, leaving little money for training, new equipment, and maintenance. It also meant an older, on average, bunch of troops. Going to war is a young man's game, but Europeans have instead turned their armed forces into another job creation program. There are some exceptions, like Britain and France, demanding that the troops remain fit and maintaining high training standards. Most European nations maintain a few elite infantry units, but these don't add up to much in terms of numbers. Only Britain and France have large "rapid reaction" forces that can be sent overseas on short notice but even these are threatened by continued budget cuts. The United States has the largest such force, and many European nations tried to expand theirs but decades of politicians spending more than they should have is catching up with most European nations. The unexpected Russian menace has changed that mentality momentarily but that is temporary. Old customs die hard.
Europe has dribs and drabs of military capabilities that could only be significant in conventional warfare if gathered together in larger, effective units.
Otherwise European defense efforts generate power within their own national borders, practically speaking. And even spending 2% of their GDP on defense, while helpful and surely the foundation of anything else, won't solve Europe's defense deficiency.
