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Duties of Third States

Eileen Denza

From: Diplomatic Law: Commentary on the Vienna Convention on Diplomatic Relations (3rd Edition)

Professor Eileen Denza

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From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2023. All Rights Reserved. Subscriber: null; date: 08 June 2023

Diplomatic immunity — Diplomatic privileges — Diplomatic missions — Recognition of states

(p. 451) Duties of Third States

Article 40

1. If a diplomatic agent passes through or is in the territory of a third State, which has granted him a passport visa if such visa was necessary, while proceeding to take up or to return to his post, or when returning to his own country, the third State shall accord him inviolability and such other immunities as may be required to ensure his transit or return. The same shall apply in the case of any members of his family enjoying privileges or immunities who are accompanying the diplomatic agent, or travelling separately to join him or to return to their country.

2. In circumstances similar to those specified in paragraph 1 of this Article, third States shall not hinder the passage of members of the administrative and technical or service staff of a mission, and of members of their families, through their territories.

3. Third States shall accord to official correspondence and other official communications in transit, including messages in code or cipher, the same freedom and protection as is accorded by the receiving State. They shall accord to diplomatic couriers, who have been granted a passport visa if such visa was necessary, and diplomatic bags in transit the same inviolability and protection as the receiving State is bound to accord.

4. The obligations of third States under paragraphs 1, 2 and 3 of this Article shall also apply to the persons mentioned respectively in those paragraphs, and to official communications and diplomatic bags, whose presence in the territory of the third State is due to force majeure.

The opinions of writers on diplomatic law had long been divided on the questions of whether a diplomat proceeding to or returning from his post was entitled to a right of innocent passage through third States, and secondly on whether when in transit through a third State he was entitled to some or all of the privileges and immunities accorded to him in the receiving State. Clear customary rules did not emerge because there were so few cases where a diplomat encountered difficulties in transit States, or where it mattered whether (p. 452) baggage privileges were extended to him as a matter of courtesy on production of his diplomatic passport or on a basis of law.

In the early period of diplomatic exchanges it was customary for diplomats intending to travel through countries where they had reason to fear interference with their free passage to seek a safe conduct. A safe conduct—which was also available to any private person—guaranteed safe transit through the territory of the State granting it, and in the case of a diplomat the sending State would certainly protest if there was any breach of the undertaking.1 An alternative basis for protection was a bilateral treaty providing for reciprocal guarantee of safe passage for the ambassadors and couriers of the two Contracting Parties.2 The fact that States concluded treaty provisions of this nature, while they did not conclude treaties providing for immunities of their resident ambassadors, strongly suggests that it was not thought that a diplomatic agent in transit was entitled in the absence of special provision to inviolability or immunity. The early writers on diplomatic law all agreed that in the absence of a safe conduct there was no obligation on third States to accord inviolability or immunity to a diplomat in transit.3 On the other hand, the ‘right of innocent passage’ seems to have been generally accepted until the end of the nineteenth century—provided that there was no war between the transit State and the sending or receiving State. In general States did not impose the control on entry of aliens into their territory which became general early in the twentieth century, and so long as there was no air travel and methods of travel were slow and unreliable, all States had an interest in maintaining a practice permitting diplomats to travel in security by the most direct route to and from their posts.

By the early twentieth century the position had changed. States increasingly reserved the right to refuse to admit a diplomat in transit.4 Although the ‘right of innocent passage’ survived in books on diplomatic law,5 diplomats were in practice expected to obtain a visa if such a visa was required for any ordinary (p. 453) person of their nationality. But States accepted that once a diplomat had been admitted he was entitled at least to freedom from arrest and detention. The transit State could refuse entry to a diplomat in transit if for any reason it found his presence unacceptable, or it could admit him with the immunities attendant on his status. The position was explained thus by Wheaton:

the inviolability of a public minister in this case depends upon the same principle with that of his sovereign, coming into the territory of a friendly State by the permission, express or implied, of the local government. Both are equally entitled to the protection of that government against every act of violence and every species of restraint, inconsistent with their sacred character.6

The right of transit became of less importance with improvement in methods of travel, in particular the development of air travel, but with safe conducts falling into disuse it became necessary for the diplomat to be given basic protection in third States solely on the basis of his status as diplomat in transit. This might be accepted on the evidence of his diplomatic passport, perhaps with a copy of his credentials. There were few occasions for clarifying whether a diplomat in transit was entitled to any further immunity—diplomats had enough sense not to pass through States where they were wanted on criminal charges or their creditors were waiting to pounce on them, and they did not stay long enough to fall foul of the authorities. If they did delay for personal reasons it was agreed that they lost their entitlement to immunity.7 Unless the diplomat had property in the transit State there was little incentive to bring civil proceedings against him, since any judgment could not be enforced against him while his appointment continued.

In several cases, however, in France,8 the United Kingdom,9 and the United States10 diplomatic agents in transit were held to be entitled to immunity from civil jurisdiction. Provision to this effect was included in the 1928 Havana (p. 454) Convention regarding Diplomatic Officers,11 and the 1929 Resolution of the Institute of International Law.12 In the Lateran Treaty of 1929 between Italy and the Holy See envoys to the Holy See were guaranteed admission to Italian territory on the basis of their national passport and a visa issued by a Papal representative abroad and were entitled to full diplomatic immunities even if their sending State maintained no diplomatic relations with Italy.13 The Harvard Research in 1932 provided only a duty to permit transit and accord ‘such privileges and immunities as are necessary to facilitate his transit’, on condition that the transit State was notified of the official character of the diplomat. Other privileges and immunities were to be a matter of comity only.14

Article 40.1 thus reflects the modern customary law. It provides no right of transit to diplomatic agents. The International Law Commission considered provision for a right of free passage, but in the light of conflicting arguments ‘did not think it necessary to go further into this matter’.15 The Vienna Conference clarified the right of the transit State to refuse passage by adding the words proposed in an amendment by Spain: ‘which has granted him a passport visa if such visa was necessary’.16 In addition to inviolability, the immunities granted to the diplomat in transit are limited to what is ‘required to ensure his transit or return’. There is thus no bar to institution of civil proceedings against him provided that he is not arrested or detained, which would in any event now be rare in any country in the context of civil proceedings. The term ‘inviolability’ probably denotes only personal inviolability and would not extend to personal property or a temporary residence such as a hotel room. His papers would, however, be entitled to the inviolability of archives of a foreign sovereign State. As for other privileges—customs privileges and exemption from baggage search may be accorded on a basis of courtesy, but are not required by Article 40. Other privileges are not required and are in any event unlikely to be relevant in the context of a transit journey.

In the case of the Former Syrian Ambassador to the German Democratic Republic17—discussed above in the context of Article 39.2—the German (p. 455) Federal Constitutional Court pointed to the requirement under Article 40 for the diplomat to obtain a visa in order to transit a third State as a form of protection for the transit State, which balanced the duty to guarantee immunity. The fact that there was no such requirement for other third States suggested that diplomatic immunity did not apply in such other third States, and supported the conclusion of the court that:

Diplomatic law as a self-contained regime, with its integrated possibilities of protection and reaction, is in principle not designed to cover the relations between diplomats and third States.

An illustration of the limited protection given by Article 40.1 occurred in 1972 when an Algerian diplomat in transit from Damascus to Brazil (though it is not certain whether this was the State where he was accredited) was found on search of his baggage at Schiphol airport in The Netherlands to be carrying quantities of grenades, rifles, revolvers, letter bombs, and other explosives. His luggage was confiscated but after questioning he was allowed to proceed on his journey. The Netherlands was then not a Party to the Vienna Convention but was generally applying its provisions and took the position that he could not be arrested or charged.18

Article 40.2 was added by the International Law Commission in response to a suggestion by the United States that the protection to be given to diplomats and their families should be extended to other members of a mission and their families.19 The Commission, however, chose to make the obligation in respect of other members of a mission and their families more limited than the immunity from arrest and detention accorded under Article 40.1. In consequence it is very difficult to see what if any are the specific duties of a transit State towards junior staff of a third country mission and their families. There is no obligation under Article 40.2 to admit them for transit and probably there is no obligation to grant them inviolability or other immunities from jurisdiction.

Article 40.3 originally formed part of the Article on communications, now Article 27, but the International Law Commission thought it more appropriate to include in one Article all the obligations of third States. The effect of Article 40.3, which is based on customary international law, is that third States are bound to accord to all communications, bags, and couriers in transit and belonging to States Parties to the Convention the full range of privileges and immunities set out in Article 27 with the exception of Article 27.7 on diplomatic (p. 456) bags entrusted to the captain of a commercial aircraft. Article 27.7 is relevant only when the bag reaches the State of destination.

Article 40.4 was introduced at the Vienna Conference by a Dutch amendment.20 In contrast to the obligations under paragraphs 1, 2, and 3 which arise where the transit State has expressly or by implication consented to transit, the obligations under Article 40.4 arise in a case of force majeure and without any consent by the transit State. The most common case of this is the forced landing or diversion of an aircraft.


The obligations imposed by Article 40 apply as between Contracting Parties to the Convention even where the transit State is not in diplomatic relations with either the sending or the receiving State. But where the transit State does not recognize the sending State as a State or does not recognize as a government the authorities who accredited the diplomat, it will in consequence not regard that person as a diplomatic agent at all, so that it will not regard itself as bound by the duties in Article 40 so far as he is concerned. Thus, for example, when in 2002 Pakistan broke off diplomatic relations with the Taliban Government of Afghanistan and escorted its former Ambassador to the frontier with Afghanistan where it handed him to pro-United States Afghan forces, the United States—which had never recognized the Taliban Government—arrested him and ultimately transported him to Guantanamo Bay.21 A person holding a diplomatic passport is also not necessarily a ‘diplomatic agent’ for the purposes of Article 40—there must also be evidence that he has been accredited to a specific State. For Article 40 to confer immunity there must in the eyes of the transit State be both a sending and a receiving State.

‘while proceeding to take up or to return to his post…’

The obligations imposed on transit States by Article 40 arise only where the beneficiary is in the course of direct passage to the receiving State or to the home State, though it is not essential that the passage should be between these (p. 457) two States. It was clearly established even before the Vienna Convention that if a diplomat made or broke his journey for purely personal reasons, such as a holiday, he could not claim any special status. In US v Rosal22 in 1960, for example, the Guatemalan Ambassador to Belgium and The Netherlands was held not to be immune from prosecution for a narcotics offence on the ground that he had flown to New York on personal business and intended to fly not back to his post but to Paris. He was not therefore ‘within the rule of international law granting immunity to a diplomat en route between the official post and his homeland’. At the Vienna Conference the United States—perhaps with this case in mind—attempted by amendment to limit transit immunity to diplomatic agents ‘in immediate and continuous transit on official duty’, but there was virtually no support for this addition.23 The wording in Article 40.1 allows a certain degree of flexibility.

There is, however, no entitlement to inviolability or immunity under Article 40.1 if the diplomatic agent remains in a transit State even if this stay is on some form of official business. (The diplomatic agent in such a situation may, of course, be entitled to immunity in some separate capacity such as representative to an international organization.) This was in part the ratio of the decision in the UK case of R v Governor of Pentonville Prison, ex parte Teja,24 already discussed in the context of Article 39.1. Teja carried a diplomatic passport and held a roving commission on behalf of the Government of Costa Rica, but as he was not accredited to or received by any one State the court held that he could not be a diplomatic agent ‘proceeding to take up or to return to his post’. As Lord Parker CJ put it: ‘He had come from Geneva and he was going back to Geneva, and indeed he had a round-the-world ticket, one might say, beginning in Costa Rica and ending in Costa Rica’. Article 40 was also invoked in the case of R v Lambeth Justices, ex parte Yusufu,25 also discussed under Article 39.1, on the basis that Yusufu while he was working in the Nigerian High Commission in London applied for and was granted a diplomatic multiple entry visa to the United States, but the Divisional (p. 458) Court did not take seriously the claim that Yusufu was a diplomatic agent in transit.

In 1979 in the case of Vafadar,26 the wife of the Ambassador of Afghanistan to India was denied immunity by the Court of Cassation in Belgium when she was arrested on criminal charges while passing through Belgium in order to visit her sick mother in Moscow. The Court of Cassation agreed with the lower court that she ‘was not accompanying the diplomatic agent, was not travelling in order to join him and did not return to his country’. She therefore had no immunity under Article 40.1. Similarly a diplomatic agent in the Zambian Embassy in Kenya who was travelling in The Netherlands but not for the purpose of taking up his post or returning to his own country was held in 1984 by the District Court of Haarlem in Public Prosecutor v JBC27 not to be entitled to immunity from a charge of smuggling heroin. In 1980 a Belgian diplomat accredited to Iraq was arrested and charged on the order of a Greek court with the murder of his wife. The shooting of the wife took place in a taxi on the way to Athens airport, whence they intended to return to Iraq. The decision may have depended more on the flagrant nature of the crime than on the reasons why the diplomat had stopped over in Athens before returning to his post.28

That the transit need not be directly between sending and receiving States for entitlement to immunity under Article 40.1 to apply was illustrated in 1977 by the case of R v Guildhall Magistrates’ Court, ex parte Jarrett-Thorpe.29 Jarrett-Thorpe was the husband of a diplomat in the Embassy of Sierra Leone in Rome. His wife had travelled to London to buy furnishings for the embassy in Rome, and it was intended that her husband would join her there to help her with luggage and to travel with her back to Rome. When he arrived he received a message that his wife had already left for Rome, and while at Heathrow airport awaiting a flight to Rome he was arrested on criminal charges. The Divisional Court held that he was ‘travelling separately in order to join’ his wife and that he was therefore entitled to immunity under Article 40.1. The court specifically rejected the argument that Article 40 applied only to transit between sending and receiving States.

Although it was not material in the Jarrett-Thorpe case, the second sentence of Article 40.1 under which members of the families of diplomatic agents derive their entitlement to inviolability and transit immunities is (p. 459) worded less precisely than the first sentence. On the facts described above, for example, Mrs Jarrett-Thorpe would not have been entitled to immunity while travelling to London or during her stay in London, while her husband ‘travelling separately to join’ his diplomatic spouse would appear to qualify. It may be, however, that the words ‘the same shall apply’ are intended to import into the second sentence of Article 40.1 the limitations as to destination which appear in the first sentence. Given the derivative nature of immunities for family members of diplomatic agents, this is probably the correct interpretation.


Adair (1929) pp 110–14; Satow (5th edn 1979) para 18.2.

For example, the Treaty of 1623 between Britain and Russia: De Intercursu Mercandisarum cum Imperatore Russiae, Rymer, Foedera vol 17 p 506.

Gentilis (1585) II ch III; Grotius (1625) II.XVIII.V; Bynkershoek (1721) ch IX; Wicquefort (1681) vol I para 29; Pradier-Fodéré (1899) vol II p 21. Martens (1827) vol I p 387 describes the case of Rinçon and Frégose, envoys of France to Venice and Turkey, who were assassinated in transit through Milan, allegedly with the complicity of the Emperor Charles V.

In 1854, for example, France detained Pierre Soulé, making clear he would only be permitted to transit if they were assured he would not remain in France: Moore (1905) vol IV p 557; Satow (5th edn 1979) para 18.3.

eg Oppenheim (8th edn 1955) vol I para 398: ‘there ought to be no doubt that such third State must grant the right of innocent passage (ius transitus innoxii) to the envoy, provided that it is not at war with the sending or the receiving State’.

(1866) s 247. See also Vattel (1758) IV.VII para 84; Genet (1931) vol II p 395; Hurst (1926) vol II pp 221–7.

Sickles v Sickles 1910 Journal de Droit International Privé 529; US v Rosal, 191 F Supp 663 (SDNY 1960); 31 ILR 389; Deak, American International Law Cases vol 19 p 166.

Bayley c Piedana et Mauroy (1840) Tribunal de la Seine, 1901 Journal de Droit International Privé 341.

New Chili Gold Mining Co v Blanco 4 Times Law Reports 346 (a doubtful precedent with conflicting dicta).

10  Holbrook v Henderson (NY 1839) 4 Sandf 619; Wilson v Blanco (NY 1889) 4 NY Suppl 714; Bergman v De Sièyes, 71 F Supp 334, 170 F 2d 360, 1947 AD No 73, where the New York court said: ‘it will ordinarily more interfere with duties to be obliged to attend the trial of an action pending in a third State than that of one pending in the State of his post’. In Carbone v Carbone (1924), 123 Misc (NY) 656, 1923–4 AD No 170, a New York court refused immunity in an action for divorce.

11  UN Legislative Series vol VIII, Laws and Regulations regarding Diplomatic and Consular Privileges and Immunities (‘UN Laws and Regulations’) p 421 (Art 23).

12  Art 5: 26 AJIL (1932 Supp) 186.

13  Text of Arts 18 and 19 of Treaty is in Satow (5th edn 1979) para 18.5.

14  26 AJIL (1932 Supp) 144, Art 15; Denza, ‘Diplomatic Privileges and Immunities; in Grant and Barker (eds), The Harvard Research in International Law: Contemporary Analysis and Appraisal (WS Hein, 2007) at pp 167–9.

15  ILC Yearbook 1958 vol II p 103.

16  UN Docs A/Conf. 20/C 1/L 319; A/Conf. 20/14 pp 209–10.

17  Case No 2 BvR 1516/96; 115 ILR 595.

18  UN Doc S/10816; 1974 RGDIP 247.

19  UN Docs A/CN 4/114 p 66; A/CN 4/116 p 83; ILC Yearbook 1958 vol I pp 172–4.

20  UN Docs A/Conf. 20/C 1/L 191; A/Conf. 20/14 pp 209–10.

21  Information from lawyers representing Abdul Salam Zaeef, the former Taliban Ambassador.

22  US District Court, Southern District of New York, 191 F Supp 663; 31 ILR 389; noted in 1961 AJIL 986.

23  UN Docs A/Conf. 20/C 1/L 276; A/Conf. 20/14 pp 209–10.

24  [1971] 2 QB 274, [1971] 2 All ER 11, [1971] 2 WLR 816.

25  [1985] Crim LR 510. Brown (1988) at p 61 describes the Meier case in which an Australian magistrate granted immunity to a Canadian national with a Tongan diplomatic passport who claimed to be in Australia to arrange a state visit by the King of Tonga. He was neither a member of any Tongan diplomatic mission nor accredited to any State, and Brown states simply that the decision was wrong.

26  82 ILR 97.

27  94 ILR 339.

28  1980 RGDIP 1079.

29  Times Law Reports, 6 October 1977.