"The Twenty Years' Crisis" is a book written by E.H. Carr in 1939, analyzing the political landscape between World War I and World War II. Carr critiques the idealistic approaches to international relations that dominated the interwar period, arguing that they failed to account for the realities of power and conflict. The book emphasizes the importance of realism in understanding global politics, suggesting that moral ideals often clash with the interests of states. Carr's work has influenced the field of international relations, shaping debates on the balance between ethics and power in global affairs.