the doctrine of international comity has been described variously "as a choice-of-law principle, a synonym for private international law, a rule of public international law, a moral obligation, expediency, courtesy, reciprocity, utility, or diplomacy. authorities disagree as to whether comity is a rule of natural law, custom, treaty, or domestic law. indeed, there is not even agreement that comity is a rule of law at all." because the doctrine touches on many different principles, it is regarded as "one of the more confusing doctrines evoked in cases touching upon the interests of foreign states."