The Twenty Years' Crisis: 1919–1939: An Introduction to the Study of International Relations is a book on international relations written by E. H. Carr. The book was written in the 1930s shortly before the outbreak of World War II in Europe and the first edition was published in September 1939, shortly after the war's outbreak; a second edition was published in 1945. In the revised edition, Carr did not "re-write every passage which had been in someway modified by the subsequent course of events", but rather decided "to modify a few sentences" and undertake other small efforts to improve the clarity of the work. In the book, Carr advances a realist theory of international politics, as well as a critique of what refers to as the utopian vision of liberal idealists (which he associates with Woodrow Wilson). Carr's realism has often been characterized as classical realism. Carr argues that international politics is defined by power politics. He describes three types of power: political power, economic power, and power over opinion. He argues that political action is based on a coordination of morality and power. Description The text is considered a classic in international relations theory, and is often dubbed one of the first modern realist texts, following in the fashion of Thucydides, Machiavelli and Hobbes. Carr's analysis begins with the optimism that followed World War I, as embodied in the League of Nations declarations and various international treaties aimed at the permanent prevention of military conflict. He proceeds to demonstrate how rational, well-conceived ideas of peace and cooperation among states were undermined in short order by the realities of chaos and insecurity in the international realm. By assessing the military, economic, ideological, and juridical facets and applications of power, Carr brings harsh criticism to bear on utopian theorists who forget to consider the exigencies of survival and competition. Carr does not, however, consider the prospect of human improvement a lost cause. At the end of The Twenty Years' Crisis, he actually advocates for the role of morality in international politics, and suggests that unmitigated Realism amounts to a dismal defeatism which we can ill afford. The sine qua non of his analysis is simply that in the conduct of international affairs, the relative balance of power must be acknowledged as a starting point. He concludes his discussion by suggesting that "elegant superstructures" such as the League of Nations "must wait