A time of change in international politics produced a change in ideas about the world. The initial post-First World War decade had reflected an essential concurrence in the mainstream literature because there was a certain degree of consensus in politics. The second decade produced no such consensus. Hence, although a composite model from basic texts of the first decade of the discipline’s formal growth could reasonably (if not very scientifically) be constructed, we were now confronted with a pattern of distinctions. Between the collapse of the League and the extension of the European war to most of the world by 1941, there were almost as many conceptual frameworks as there were authors to explain the meaning of rapidly shifting events.