I'm pretty certain that Germany is well past the economic instabilities and power-grabbing Nazi leftovers of the late-1940s/early-1950s that required that the Germans be "kept down".  If Europe was worried about such things, they'd have never let Germany into the EU where their economic and technological influence could achieve the same goals as a strong military did 80 years ago.

Further, why assume that any one nation would have to build up a military to defend the rest of Europe?  NATO was a European idea based on mutual self-defense - so that one nation never rose to that level and so that they could defend themselves against the Soviets.  Their task is to work toward a mutual capability, not hide under the shadow of one superpower.  But, if they were to allow Germany to grow to that level and hid behind the Germans (much like they currently do with the US), would that not be their own decision to make regardless of what the rest of the world thinks?