"Actually, there is nothing particularly ancient about either the peoples of Europe or their supposed right to political autonomy. The claims to sovereignty that Europe is seeing in Eastern and Central Europe today are a creation of the nineteenth century, an age that combined the romantic political philosophies of Rousseau and Hegel with 'scientific' history and Indo-European philology to produce ethnic nationalism. This pseudoscience has destroyed Europe twice and may do so yet again. Europe's peoples have always been far more fluid, complex, and dynamic than the imaginings of modern nationalists" (Geary 13). One problem with the idea of ethnic 'self-determination' that Geary's book highlights is that it is virtually impossible to draw the line where it ends. "Surely, if Lithuanians or Croats have their own language, their own music, and their own dress, then they have a right to their own parliament and their own army" (Geary 9). But then what about Chechnya in Russia? How far can states break down into endless factionalism? The right to national self-determination was one of the diplomatic weapons that the U.S. used against the Soviet Union, alleging that Soviet-controlled states had a right to be independent nations. However, after the dissolution of the Soviet empire, this nationalistic concept almost immediately generated problems, most notably in the former state of Yugoslavia, where Serbs, Croats, and Bosnians all fought for what territories...

This can be seen in the modern, European xenophobia regarding the influx of non-white immigrants to their borders. It is essential to understand that 19th century concepts of nationalism did not 'awaken' long-simmering ethnic identities, rather the ideas of the century created the concept. The real origins of European nations are in fragments of tribes that reconfigured themselves. Then, later generations told different, often competing myths of origin to justify the power of their nation over others. Even the United States has become to believe these myths and perhaps the U.S., a very young nation, is 'proof' of how easy it is to create and believe false myths of national birth, given how much talk there is in this nation of immigrants about what constitutes a 'real' American. But while Geary forcefully unpacks the myths of nation-building in early Europe, he also has little hope that knowing these myths will have much of a difference in ending bloodshed: "Failing even this, historians have a duty to speak out, even if they are certain to be ignored" (Geary 14).
Reference

Geary, Patrick. The Myth of Nations: The Medieval Origins of Europe. Princeton: Princeton

University Press, 2003.