One of the most significant and helpful developments in the study of the subject of International Relations and Politics in the period following World War II has been the intensification of a conscious and deliberate attempt to arrive at an understanding of international political reality through theoretical investigations. In an important way, the growing emphasis on this study in a conceptual framework has overshadowed the old style of presenting this subject in the form of a diplomatic history of some major Western powers. Though it is widely realised that an orderly and comprehensive study of all the relevant aspects of international relations and politics in a theoretical perspective has not yet appeared, and it is also feared that such endeavours may not have the desired success, yet a very large number of scholars, particularly of the United States, have been engaged in their advanced academic pursuits so as to offer a plausible explanation of their involvements with the issues of why to theorise and how to theorise. The developments of the Post-Cold War era have stimulated the scholars of this discipline to revisit old concepts, re-evaluate traditional assumptions, and invent new strategies and paradigms for the sake of a better and updated study of international relations and politics. This discipline has now a new agenda embracing a vast range of policy issues and covering a host of new themes as security, order, freedom, equality, justice, welfare etc. which ought to prevail in the new international political and economic order. It is all the more necessary in the present age of globalisation and liberalisation. The startling point is that now the study of this discipline is growing like a profoundly normative enterprise at the expense of realism that had dominated the era of the Cold War. The author has taken note of all these developments and ventured to tread the path with a view to making the task of the readers easier and more interesting.