Projecting their own experience onto the rest of the world, Americans generally belittle the role of ethnic nationalism in politics. After all, in the United States people of varying ethnic origins live cheek by jowl in relative peace. Within two or three generations of immigration, their ethnic identities are attenuated by cultural assimilation and intermarriage. Surely, things cannot be so different elsewhere.
Americans also find ethnonationalism discomfiting both intellectually and morally. Social scientists go to great lengths to demonstrate that it is a product not of nature but of culture, often deliberately constructed. And ethicists scorn value systems based on narrow group identities rather than cosmopolitanism.
But none of this will make ethnonationalism go away. Immigrants to the United States usually arrive with a willingness to fit into their new country and reshape their identities accordingly. But for those who remain behind in lands where their ancestors have lived for generations, if not centuries, political identities often take ethnic form, producing competing communal claims to political power. The creation of a peaceful regional order of nation-states has usually been the product of a violent process of ethnic separation. In areas where that separation has not yet occurred, politics is apt to remain ugly.
A familiar and influential narrative of twentieth-century European history argues that nationalism twice led to war, in 1914 and then again in 1939. Thereafter, the story goes, Europeans concluded that nationalism was a danger and gradually abandoned it. In the postwar decades, western Europeans enmeshed themselves in a web of transnational institutions, culminating in the European Union (EU). After the fall of the Soviet empire, that transnational framework spread eastward to encompass most of the continent. Europeans entered a postnational era, which was not only a good thing in itself but also a model for other regions. Nationalism, in this view, had been a tragic detour on the road to a peaceful liberal democratic order.
This story is widely believed by educated Europeans and even more so, perhaps, by educated