Diplomatic immunities ratione materiae under the Vienna Convention on Diplomatic Relations: towards a coherent interpretation
Rules of diplomatic immunity, which nowadays are enshrined in the Vienna Convention on Diplomatic Relations, play an important role in interstate diplomacy because they ensure the efficient performance of diplomatic functions. This thesis investigates a particular form of diplomatic immunity — diplomatic immunity ratione materiae. Unlike diplomatic immunity ratione personae, which pertains to the personal status of a diplomatic agent, diplomatic immunity ratione materiae depends in essence on the official nature of a particular act In practice, however, the determination of diplomatic immunity ratione materiae may meet with many conceptual and practical difficulties. For one, it is not always easy to distinguish the official acts of a diplomatic agent, who represents the sending State in the receiving State, from his or her private acts. In case of disagreement between the two States, questions may also arise as to who has the authority to make a final determination. The Vienna Convention does not offer much guidance on these issues; on the contrary, the Convention complicates them by employing, without adequate explanation, distinct formulas for different kinds of diplomatic immunity ratione materiae. This thesis examines these formulas in detail. On a general level, it is submitted that diplomatic immunity ratione materiae for certain types of activity constitutes not only a procedural bar to court proceedings but also a substantive exemption of individual responsibility. More specifically, it is argued that each formula must be understood in the light of the rationale behind immunity, the type of immunity concerned, and the specific functions or duties performed. In case of controversy, weight should be given to the opinion of the sending State, although the authority to make a decision lies ultimately with the court of the receiving State.