Reciprocity and Diplomatic and Consular Law

The principle of reciprocity is deeply embedded in the very idea of diplomatic and consular law. This is because, as E. Denza explains, States’ representatives abroad are in some sense always hostages. This principle is however somewhat limited because of the apparent transition from bilateralism to community interest. Is diplomatic law between States not regulated nowadays by the Vienna Convention on Diplomatic Law, which is binding for nearly every State member of the international community? Nevertheless, bilateralism is still relevant in diplomatic and consular relations between States. There are always the receiving and the sending States, and in their vast majority disputes related to diplomatic and consular law are bilateral in nature. It manifests itself in, for example, reciprocal restrictive application, which is enshrined in Article 47 of the Vienna Convention on Diplomatic Relations and Article 72 of the Vienna Convention on Consular Relations. In case of quasi-diplomatic relations with international organizations, the principle of reciprocity seems to be barely applicable. It means that the principle of reciprocity in diplomatic and consular law boils down to the general characteristics of States as subjects of international law. Thus, the principle of reciprocity, as a relevant part of diplomatic and consular relations, is actually inherent to coexistence between States. This is why diplomatic and consular law reveals a key element of relations within the international community. After all, diplomatic and consular law is a branch of international law ensuring the functioning of that community. Reciprocity and self-help seem to be inevitable prima facie when judicial dispute settlement is not available. Retortions in relation to members of the diplomatic mission and the consular post are very often applied in relations between States. Development of diplomatic and consular law also reveals another regularity. Namely, reciprocity played a significant role in the emergence of particular customary rules of diplomatic and consular law. But with the emergence of these rules, the significance of reciprocity has diminished—tax exemptions are an example of this. Yet even if reciprocity is wiped out in some areas of diplomatic and consular law (while still being applicable in other cases), it does not prevent States from threatening reprisals.