Book excerpt: This is the fiftieth volume of The Canadian Yearbook of International Law. The contents of this special anniversary edition reflect the diversity of Canadian and international thought, opinion, and practice on current problems of international law. Included are a retrospective examination of Canadian approaches and contributions to international law during the Yearbook's first fifty years as well as cutting-edge analyses and commentary on a wide range of issues, such as the use of battlefield biometrics, the cultural dimensions of sustainable development, Omar Khadr's combatancy and child-soldier status, and immunities for gross violations of international human rights.