Foreign policy decisions are influenced by many factors. The real world is complex and many variables have to be considered when making a decision. A psychological approach to decision-making facilitates the understanding and explaining of the complexity of foreign and global policies precisely because of the prolonged transitional stage of the contemporary international system. The course of world politics is shaped by the decisions of leaders. Uncertainty involved in decision-making in foreign policy can relate to the motivations, beliefs, intentions or calculations of the opponents. If it is not possible to understand how decisions are made, then maybe it is at least feasible to understand these decisions and, perhaps more importantly, predict various results with regards to international politics. This book provides a new perspective on the study of international relations by analyzing the subjective elements (idiosyncrasies) that occur in decision-making at the individual level. The use of psychological methods of analysing the foreign policy decision-making process proposes a necessary investigation path into international relations.