A striking trend in contemporary world politics is the apparent erosion of political unity in so many different places. In the Middle East, we’ve seen the upheavals of the Arab Spring and the continuing bloodbaths in Syria, Libya, Yemen, and elsewhere. In Europe, support for the European Union continues to drop, Great Britain may vote to leave it, and Scotland might still decide to exit the United Kingdom. Here in the United States, we have a level of bitter partisanship not seen for many decades, the two main political parties are themselves deeply divided, and the presumptive GOP presidential candidate is a rank amateur (in several senses of that term). To say “the center cannot hold” seems like an understatement these days...