Nationalism is primarily a political principle, which holds that the political and the national unit should be congruent.
(Ernest Gellner) 1
In its most familiar and historically potent form, nationalism is the principle that the nation is the ground of political sovereignty and that political sovereignty is the right and destiny of the nation. This principle is satisfied when and only when nation and State come together as the nation-state.
Nationalism has played an enormous role in modern history. World maps have had to be redrawn—and are still being redrawn—in the effort to make state borders coincide with what are conceived to be the boundaries of the nation. Large numbers of people have been prepared to make great personal sacrifices—up to and including life itself—in the struggles needed to achieve or defend the political sovereignty of their nation. At the end of the twentieth century, it does not need emphasising that many have been prepared to commit unspeakable atrocities in the name of the nation. However, it should also be remembered that those of us who go about our business in politically stable countries rely on this principle when we draw a comfortable moral line between the claims of our compatriots and those outside our national boundaries.
But what is the nation? And what is it about the nation which supports—or has seemed to support—the claims made on its behalf? If the nation is the source of political authority, what is the source of its political authority? Why is it our nation, rather than our class, religion or political commitment, that demands political recognition?