The Liberal International Theory Tradition in Europe promotes liberalism and revives its classical IR tradition, predominantly by presenting liberalism in constructive ways but only with regard to the historical context of Europe in the last 100 years. Thus, this monograph can be criticized for not being objective as it ignores significant critiques of the classical liberal tradition; for instance, the critique that the tradition is incompetent in dealing with religious and cultural differences domestically and internationally.
The Muqaddima (Prolegomena) is the main work that made Ibn Khaldun (1332-1406) eminent not only in historiography, civilization studies, anthropology, and sociology, but also in philosophy, economy, demography, and other fields of study.
A profound understanding of American foreign policy depends upon a thorough and a rigorous theoretical understanding of the ideology that stimulates and determines it. Liberalism claims that spreading liberal democracy across the world can be accomplished through an open international economy and international institutions that promote peace in the international system. Throughout his mainly theoretical contribution, John Mearsheimer argues that on the contrary, liberal democracy harms the U.S. and the international system.