The 1961 Vienna Convention on Diplomatic Relations outlines the rules of diplomatic law, ratified by Canada in 1966 and implemented by the Foreign Missions and International Organizations Act. The Convention codifies the rules for the exchange and treatment of envoys between states, which have been firmly established in customary law for hundreds of years. It has become an almost universally adopted Convention with 179 states party to it.
The Vienna Convention on Diplomatic Relations is fundamental to the conduct of foreign relations and ensures that diplomats can conduct their duties without threat of influence by the host government. In particular, the Convention establishes the following:
As is stated in the preamble of the Convention, the rules are intended to facilitate the development of friendly relations among nations, irrespective of their differing constitutional and social systems. The purpose of such privileges and immunities is not to benefit individuals but to ensure the efficient performance of the functions of diplomatic missions.
The Convention requires diplomats to obey local laws; however, the only sanction permissible under the Convention, in the absence of a waiver of immunity, is expulsion. This prevents the potential abuse by local authorities of the power of a state's law enforcement system. Reciprocity also forms an effective sanction for the observance of the rules of the Convention.