Love the things I hear of Europe. Seems like you guys don't spend most of your budget on things to kill people- that's inspiring- almost as if you guys learned something from wwii about the importance of treating the average person with care and respect.
The US took the de-facto policing role after Europe's industries were laid to waste or otherwise prohibited from war-making after the World Wars (obviously not as strenously as Japan, who got a constitution that does the same). Not to mention that staying less aggressive helped to avoid provoking the Soviet Union, which occupyed a significant portion of the continent. For good or ill, Western Europe outsourced almost all of its military as a matter of immediate necessity and, shortly after, Cold War politics.
I can't speak to the change in culture in the intervening century or so, though the soviet political model seems to not be completely out of favor in influencial parts of their Union.