International Tax law is a constantly changing field, and this book is just a glimpse of the current international tax framework. The purpose of this book is to give the reader an understanding of how the international taxation system fits into the larger framework of international law. The interplay of the international tax system of law with other regimes, such as international trade law or investment law, is thus the emphasis. Furthermore, this book describes the key components of the International tax negotiation system, which is a highly dynamic system of partially harmonized tax rules. International Tax Law must be understood not just by individuals who live in wealthy countries, but also by those from developing countries. On the on hand, developing countries have served as a test bed for the interaction of several non-harmonized tax regimes in a shared market.