Twenty-five years ago, I wrote the essay "The End of History?" for a small journal called the National Interest. It was the spring of 1989, and for those of us who had been caught up in the big political and ideological debates of the Cold War, it was an incredible moment. The piece appeared a few months before the fall of the Berlin Wall, right about the time that pro-democracy protests were taking place in Beijing's Tiananmen Square and in the midst of a wave of democratic transitions in Eastern Europe, Latin America, Asia and sub-Saharan Africa.

I...