In his essay on philosophical and political thoughts of Karl Riezler, (Chapter 10, “Karl Riezler,” What is Political Philosophy? by Leo Strauss), Leo Strauss makes the following comment on nationalism (Page 238):
While nationalism is as such theoretically unsatisfactory, it may still supply us with the best available framework for understanding the present political situation and for enlightening political action within a world that is dominated for all the foreseeable future by nationalism. Nationalism is certainly superior for these purposes, not only to the constructs of the legalists, but likewise to a certain sociology which is guided by the notions of “society” and “growth.” For that sociology is apt to make us forget two things which the nationalist never forgets. Societies are still, and for the foreseeable future, national or imperial societies, closed off from other societies by unmistakable and formidable frontiers which have been established by wars rather than by other means; and if societies “grow” there is no guarantee whatsoever that they will not take away the light of the sun from others: he who preaches “growth” without thinking of the term of growth, of the peak beyond which there cannot be growth, preaches war.