The Vienna Convention on Diplomatic Relations (VCDR) was signed at the height of the Cold War more than fifty years ago. The agreement and its negotiation have become a cornerstone of diplomatic law. A Cornerstone of Modern Diplomacy, which is based on archival research in the National Archives (London), the Austrian State Archives (Vienna) and the Political Archive (Berlin), delivers the first study of the British policy during the negotiation of the key convention governing diplomatic privileges and immunities: the 1961 Vienna Convention on Diplomatic Relations. The book provides a complete commentary on the political aspects of the codification process of diplomatic law. By clearly presenting the case with accessible analysis, author Kai Bruns makes the relations between international law and politics understandable, stressing the impact of the emergence of the third world in UN diplomacy. This unique study is a crucial piece of scholarship, shedding light on the practice of United Nations conference diplomacy and the codification of diplomatic law at the height of the Cold War.