Nationalism is the supreme and potentially the most dangerous manifestation of romanticism - the elevation of the nation to the supreme value before which all other values must kneel. Isaiah Berlin distinguished between two forms of nationalism. The first is a sense of belonging and of collective identity. The second feeds upon the first but mutates into a pathological condition after a nation suffers collective national humiliation at the hands of it's external enemies.
The development of nationalism can be read though the volumes of Haman, Fichte and Burke who all unintentionally contributed to it's growth. Hamann and Fichte persuaded many that men belong to a particular and distinct social group whose way of life differs from others and that the values which men hold were shaped by national culture, national language and national ways of life. Burke contributed by comparing a society to that of a biological organism whose proper development was supreme value necessary to prevent decadence and ruin of the nation state to cancerous influences. On this view, all values and standards must of necessity be those intrinsic to a specific society while appeals to universality rest on a false view of the nature of man and of history. Those opposed were viewed as cancer threatening the collective integrity of the nation state.
This is the ideology of organism, loyalty, the volk as the true carrier of that nation's values, integralism, historic roots, the national will: it is directed against the forces of disruption and decay categorized in the pejorative terms used to describe the application of methods of the natural sciences to human affairs as 'of critical analytic' reason, 'cold' intellect, destructive 'atomizing' individualism, soulless mechanism, alien influences, shallow empiricism, rootless cosmopolitanism, abstract notions of nature, rights which ignore differences of cultures and traditions - in short the entire typology and category of the enemy which the pages of Hamann and Burke, reaches a climax in Fichte and his romantic followers, is systematized by Maistre and Bonald, and reaches a new height in our own century in the propagandist writings of the First and Second World Wars and the anathemas of rationalist and Fascist writers, directed at the Enlightenment and all its works. - Isaiah Berlin*.Nationalism was not well understood even at it's peak in the early 20th century. Liberals viewed it as as a passing phase, the consequences of national consciousness held down and forcibly repressed by deposit rulers aided by subservient churches. Communists dismissed it as a false form of consciousness, a distraction from the international struggle of the working class. The religious churches dismissed it as an idol, the false worship of the nation state over God. In all cases, nationalism was viewed as a passing sickness. But they were wrong: nationalism persists.
The cures were as numerous as the analysis. Worshiping God rather than the state would dispel romantic nationalism. Free markets would rid the world of irrational national worship as differences between nations vanished through mutual cooperation and prosperity. Human rights and cosmopolitanism would erode the appeal of parochial nationalism. In all cases the cure failed.
Nationalism, in both the forms identified by Berlin, is still a motivating force in the modern world. I see the huge outpouring of irrational anger in the Islamic world over perceived insults by the West as the second pathological form of nationalism.