Protection is essentially nationalistic. Its ideal is a nation industrially strong and self-sufficient to a high degree. Any force that increases the spirit of nationalism increases also the desire for additional industrial strength. Illustrations from the history of our country are illuminating. Every foreign war, except the one with Mexico, has been the direct cause of an increase in tariff rates or of a maintenance of rates already high. The cause is not far to seek. War necessarily increases the dependence of a country on its own industries. Besides, it knits the various sections into a closer union. Hence, there arises a general desire not only to maintain the increased self-sufficiency reached during the stress of war, but also to protect those industries which the war itself has brought into being.