Offering a unique conceptual approach to the Law of Treaties this insightful Research Handbook not only sets out the foundational issues, but identifies tensions within the field, including formalism vs flexibility, integrity vs flexibility, and uniformity vs specialisation, to name a few. It seeks to define and re-define the dimensions in which Treaty law operates, tracing its fault-lines and the challenges it faces, such as breaches, regime-collisions, state succession and armed conflict. Representing a broad range of jurisdictional and ideological perspectives, the Research Handbook provides a diverse and stimulating approach to international treaties.