Although the term national interest has long been used in reference to the foreign policy goals of nations, there has been no generally agreed upon definition of the concept; as a result, Donald E. Nuechterlein contends, there has been a tendency for foreign policy to be determined by institutional prejudice and past policy rather than by a systematic assessment of national interests. By what criterion does a President decide that a given interest is or is not vital-that is, whether he must cont