Europeans love to celebrate anniversaries, especially those commemorating a terrible past overcome. This year will offer many such moments, marking as it will 100 years since the outbreak of World War I, 75 years since the beginning of World War II, and, most uplifting of all, a quarter century since the fall of the Berlin Wall. Such milestones are bound to make everyone feel good about European unity.
But another important anniversary is less likely to be celebrated, precisely because it would put a damper on those good feelings. Ten years ago, eight eastern European states joined the European Union, followed by Bulgaria and Romania three years later. Europe seemed to have overcome not just Cold War divisions but also deeper historical differences. The EU had brought East and West together, consolidating the fragile democracies that had emerged from the fall of communism.