The war in Yugoslavia was not so long ago, for one thing.
For another, Hungary got itself a nice extreme right regime that seems rather keen to transform the country into an authoritarian state. What if they decide, at some point, that the land occupied by some of the Magyars in neighboring countries should really belong to Hungary again?
Keeping the peace in Europe is far from a finished project.
Given the resurgence of nationalism and right movements holding anti-immigration feelings in Europe right now, that's far from an universal opinion. According to these guys, our gates are wide open and the barbarians are breeding in our backyards. Barbarians being, of course, undesirable immigrants from poor third-world countries, not cool white guys from across the pond.
We still have the same "barbarians" as we always had. For the last two decades we just happened to be in a little better relations with them.
There is currently a war in progress in Libya in which one side is supported by the European forces. In 2008 Russian army entered parts of Georgia, mere 15 years after the Red Army was pulled from Eastern Europe.
Nothing changed. It never does.
> I think the kind of large scale war you talk about is permanently over
I agree that large-scale warfare is currently not very likely but I don't think it was ever that common as the twentieth century had led us to believe.
With regard to the rest of the western world, I think the kind of large scale war you talk about is permanently over -- both because it would be far too expensive for everybody and because there is no winning a nuclear war.