Disenchantment with moral abstractions as the hallmarks of enlightened foreign policy has recently revived infatuation with the slogans of “national interest,” “power politics,” and “balance of power.” Until the eve of World War II, these ideas had been recessive—at times moribund—for at least half a generation. Naive belief in the efficacy of professions of good will, reliance on weak instruments for effectuating simply noble intentions in the complex realms of policy and practice, and contentment with lofty exhortations, had too often become the directives of policy unconcerned with the harshness of politics or the intricate give-and-take of sustained diplomacy.
Since the Republic's inception, statesmen have proclaimed national interest as the firmament on which our foreign policy rests. To that concept they have repeatedly referred as a guide and rationale for action in foreign affairs. Over the years the concept of national interest has been endowed with a varied and changing content. Therefore, interpretation has been a matter of historical, rather than etymological, enquiry. Certainly, a single dictionary definition will not do. Nevertheless, while dominant meanings at different moments and a long-term trend in the development of meaning are alike discoverable, or imputable, the actual meaning in our own day rests largely on the setting of current controversies. A particular concept of the national interest, therefore, is not “automatically” warranted and acceptable by appeal to tradition and great names, any more than by formal definition.