The matter of the inviolability of a diplomatic mission was previously clouded by the perception that the territory of the sending state extended to the premises of a mission within the receiving state. Forsyth
66 refers to the origin of the rule of diplomatic immunity as follows:
The rule of diplomatic immunity may be traced to one of three theories. According to Grotius, it was based on the notion of extraterritoriality; ie the premises of a diplomatic mission represented an extension of the territory of the sending state. Closely related to this was the idea that the mission was a personification of the foreign sovereign and, on the same ground that the sovereign immunity might be claimed, so, too might diplomatic immunity be claimed. Today, however, it is more widely accepted that diplomatic immunity is based on the simple necessity of enabling the mission to perform its functions properly and efficiently. On this understanding, immunity is normally applicable only in respect of official acts connected with the mission.
67
In
Santos v Santos68 the court had to decide on the rule of diplomatic immunity. The court held that "diplomatic immunity had, in the past, been based on the notion of extraterritoriality, ie that the premises of a diplomatic mission in the receiving State represented an extension of the territory of the sending State". The court compared the views of a number of modern writers on international law
69 and held that "
t was recognised that diplomatic immunity formed an exception to the principle of territorial jurisdiction, and this exception rested on the rule of international customary law".
In conclusion the court based its judgment on the view of Akehurst,70 confirming that: "[D]iplomatic premises are not extraterritorial: acts occurring there are regarded as taking place on the territory of the receiving State, not on that of the sending State". The fiction of extraterritoriality has thus been cleared. "Customary international law is law in the Republic unless it is inconsistent with the Constitution or an Act of Parliament."71 The premises of the diplomatic and the consular corps are regarded as the territory of the receiving country. The laws of South Africa apply to citizens as well as to foreigners who are employed in South Africa.
The extent of diplomatic immunities is regulated by articles 29 and 30 of the VCDR. "The person of a diplomatic agent shall be inviolable. He shall not be liable to any form of arrest or detention. The receiving state shall treat him with due respect and shall take all appropriate steps to prevent any attack on his person, freedom or dignity." The private residence of a diplomat is also protected by the same right to inviolability as the person and the mission's premises. Article 31 affords diplomatic agents and their families72 immunity from criminal jurisdiction by the receiving state, from giving evidence as a witness, and from civil and administrative jurisdiction. There are three exceptions to article 31(1) of which sub-section 31(1)(c) may be relevant to this article: diplomatic immunity is not granted in cases of "an action relating to any professional or commercial activity exercised by the diplomatic agent in the receiving state outside his official functions". "Commercial activity" is not defined in the VCDR, given the practical nature of international law.