 Realism is thus more than a static, amoral theory, and cannot be accommodated solely within a positivist interpretation of international relations. It is a practical and evolving theory that depends on the actual historical and political conditions, and is ultimately judged by its ethical standards and by its relevance in making prudent political decisions (Morgenthau 1962). Realism also performs a useful cautionary role. It warns us against progressivism, moralism, legalism, and other orientations that lose touch with the reality of self-interest and power. Considered from this perspective, the neorealist revival of the 1970s can also be interpreted as a necessary corrective to an overoptimistic liberal belief in international cooperation and change resulting from interdependence.