Many have called the decade between the fall of the Soviet Union and the attacks of 9/11 a "holiday from history." The truth is closer to the opposite. The Cold War years, while historic in a literal sense, were something of a great parentheses, a sharp departure from historical norms. Communism was a transnational ideology imposed on nationalist movements. That's why every supposedly communist movement eventually became nationalist once in power. Still, the rhetorical and psychological power of communist ideology, combined with the fear of nuclear war, made international relations seem like a sharp break with how foreign affairs worked before 1945 -- or 1917.
It turns out, the Berlin Wall wasn't blocking us from a new world order, it was holding back the tide of history. Western Europe was especially slow to realize this. Its politicians and intellectuals convinced themselves that they had created a continental "zone of peace" through diplomacy, when in reality they were taking U.S. protection for granted. They let their militaries atrophy to the point of being little more than ceremonial.
The contrast with Russia and China (not to mention Iran and Saudi Arabia) is amazing. In Moscow and Beijing, they still believe foreign policy is about military and economic power, "spheres of influence," formal alliances and political control. In Western Europe (and much of this administration), it's about moral authority, international norms and other kinds of "soft power." Soft power is great, but it's useless against people who only respect hard power. And that lesson predates the Cold War by a few millenniums.