Extracts from Daniel J Levinson, in Bramson and Goethals, "War", 1968.

Levinson refers to the people of the USA as "American", ignoring most of the nation of the continent of America ias if they do not exist. It was typical of thw time and remains so for many. In these extracts I try to remind people, at the risk of being tedious,  that there are more than just US Americans on that huge continent, even though the Monroe Doctrine calls it the USA's "back yard" They are, in Levinson's terms mere "outgroups".

Levinson extracts...

»[US] American people tend to be relatively unsophisticated about and only partially involved in foreign policy issues.

The [US] American nation as a symbol is glorified and idealised; it is regarded as superior to other nations in all important respects...
Like other forms of ethnocentrism, [nationalism] is based on a rigid and pervasive distinction between ingroups and outgroups. The primary ingroup in this case is the [US] American nation: all other nations are potential outgroups...
Other nations are seen as inferior, envious and threatening. At the worst, they are likely to attack us; at best, they seek alliances only to pursue their own selfish aims and to "play us for a sucker". Ethnocentric ideas about human nature rationalize a belief in the inevitability of war.
"Human nature being what it is and other races being what they are", so the reasoning goes, 'some nation is bound to attack us sooner or later'. Given this "jungle" conception of international relations, our best policy is to be militarily strongest of all nations so that no one will attack us.

Perhaps the two main forms that [US} American nationalism has taken are isolationism and imperialism, though the two often go together. The guiding image of isolationism has been that of "Fortress America"; its aim is a nation which is militarily impregnable and culturally isolated. Imperialism on the other hand, is prepared to make foreign alliances and commitments, and it frequently uses internationalist terminology. Its aim, however, is the kind of "American Century" in which the development and and reconstruction of other nations can proceed only in terms set by us, for our supposed economic and strategic advantage. Isolationism and imperialism sometimes merge into a single approach as the lines of [US] American defence are conceived to to move outward into Europe and Asia as we extend support for all governments, whatever their character, in exchange for military support.

Nationalists and internationalists show characteristic differences in ideology spheres apparently far removed from foreign policy and intergroup relations. Nationalism is associated, for example, with an autocratic orientation toward child-rearing, husband-wife relations, and other aspects of family life. Nationalists are inclined to conceive of the family in hierarchical terms. They regard the husband as properly dominant over the wife, the parents as strong authorities requiring obedience and respect above all from their children. They tend to be moralistic and disciplinarian in their child-rearing methods and to be guided by rigidly conventionalized definitions of masculinity and femininity.
Nationalism is associated with certain patterns of of religious ideology, notably those that may be characterised as fundamentalistic or conventionalistic. In these religious orientations God is regarded as a kind of power figure [father] who rewards the virtuous and punishes the sinful and who can be directly appealed to or ingratiated. Great emphasis is placed on the efficacy of ritual, and the  precepts of ingroup religious authority are taken literally and unquestioningly.

Nationalism appears most commonly within an autocratic approach to the social world. This approach embraces not only the domain of international relations but the individual's views concerning religion, family, politics, and other aspects of social life as well.

The classic description of [US] American character by de Tocqueville, Bryce and others have brought out two sharply contrasting sides. On the one hand they, they find such traits as anxious conformism, emphasis on socially defined success, a tendency to escape into the crowd rather than look within, and emphasis of work over leisure, on quantity over quality, on varied activity rather than deep experience. [On the other hand are some equalitarian traits actually largely appearing within the overall authoritarian condition].«