To take your point to it's logical conclusion would mean, as we're so happy-clappy, busily trading and mutually respecting ourselves, that there would be no need for NATO, as the scenario of war is unthinkable. I understand what you're saying about war being less likely between member states, but that is not the point being debated; Pirate stated that there has been no war in Europe for 50 years because of the EU, (or inferred that). My point is that there has been no war because the protection towards allied states is provided by NATO.
If the Soviet Union had invaded, the EU treaties about who can move where, or which commodity can be traded there, would be meaningless, the protection would come from NATO/ America,( the largest member ). War between members of the EU is unlikely, for sure, but a war targeted against Europe would involve the allied military command, which is NATO. Should Britain pull out of the EU, do you think that our defense would be compromised because we're not in the EU? Of course it wouldn't, neither would Norway's, the protection doesn't come from Brussels.