Some see a continuing struggle between Germany and Russia for mastery of Europe, a struggle that marked both world wars and continues today, and not just in Ukraine, where a century ago its people fought on both sides. Others see World War I, at least as it began in Sarajevo, as the third Balkan War, while the post-Cold War collapse of Yugoslavia and its multinational, multicultural, multireligious model continues to present unresolved difficulties for Europe, in Bosnia, Kosovo and beyond. Similar tensions persist in Northern Ireland, the rump of Ireland's incomplete revolution that began with the Easter Rising of 1916.