This article revisits an old debate which still persists in the study as well practice of international politics: the view that ethics and even norms are irrelevant as well as damaging in foreign policy decisionmaking; and the opposite view which regards ethics and norms indispensable and unavoidable in international political theory and praxis. First the views of classical realism are presented followed with the views of modern realism, with emphasis on their main arguments for discarding ethics. Then the counterarguments are presented in considerable detail, the aim being to show that they are more convincing than the views of the realists. The article concludes with a succinct depiction of normative international relations or international ethics which has burgeoned as a field from the 1990s onwards.