To continue the literary analogy, consider the library at Belgium's Leuven University. Make that two libraries. German armies had burned down Leuven's library in the two world wars, and it was rebuilt after each. But then in 1970, the last time the Flemings and the Walloons got seriously restive, the million-volume collection was carved into two: Odd-numbered books remained on the original campus in the Dutch-speaking part of the country, while even-numbered books went to a new Francophone school built in a field 17 miles to the south. Thirty-seven years later, Belgium's national identity is still so elusive, so fragile...