International relations are involved in an undesirable and wrong order, at present time, which could be the origin and cause of fundamental harms on humanity. Therefore, it is necessary to propound firm principles for regulating the relationships among states and nations, and new laws and regulations be enacted at international level. The spirit of Islamic laws could be one of the pillars of this new foundation. The aim of this book is to enumerate the principles of Sufi foundation of international relations in Islam. Perhaps the delicateness, truthfulness, and righteousness of Islamic Sufism, which is the gist of thoughts of humankind's guardians during thousands of years lead and direct the thoughts, writings, and speeches of scholars and researchers to these viewpoints, and consequently a new sets of thoughts, for international relations processes in the world, to be defined and codified. This book introduces theosophical views and standpoints of Islamic Sufism about the essential topics of international relations, such as public international law, foreign policy and diplomacy, and puts several principles forward that can be used as the basis for codifying new international law.