This handbook is for the non-specialist in international law who needs to gain a working knowledge of its central principles and rules. It will, for example, help you to understand the differences between often-misunderstood ideas such as diplomatic vs. state immunity. In a world of overlapping legal systems created by international and national courts and tribunals, this is a practical guide to how international law is applied to other branches of law. It is written by an expert international lawyer, who uses his professional experience to focus on how the law is created by states and international organisations, and how they apply these laws to manage day-to-day problems. This new edition retains a concise, user-friendly format that will help you to grasp central principles such as jurisdiction and the law of treaties, as well as the international law of more specialised topics such as human rights, terrorism and the environment. With a background including thirty-five years as a legal adviser to the Foreign and Commonwealth Office, Anthony Aust is a consultant on international law to governments, law firms and international organisations. He has also taught international law at the London School of Economics and at other universities.