The Strait of Hormuz Giuseppe Cataldi* 1. Introduction. The legal regime of international straits Historically, international maritime trade has developed through the use of the shortest navigable route between ports. This involved passing through straits, understood as a natural, narrower route between two parts of the sea. The International Court of Justice (ICJ), in its judgement of 9 April 1949 in the case of the Corfu Channel (United Kingdom of Great Britain and Northern Ireland v People’s Republic of Albania),1 rec- ognised the customary value under international law of the right of all ships to innocent passage through ‘international straits’, specifying that these should be understood as those straits not only abstractly suitable for international navigation, but in respect of which there existed a long- standing practice of use by a significant number of ships. The 1958 Ge- neva Convention on the Territorial Sea and the Contiguous Zone (1958 Geneva Convention)2 dedicated only paragraph 4 of Article 16 to the in- nocent passage through straits, providing that such passage in straits ‘which are used for international navigation between one part of the high seas with another part of the high seas or the territorial sea of a foreign State’ could not be suspended by the coastal State. Compared to the 1949 ICJ ruling, the rule was explicitly extended to straits connecting the high sea with territorial waters. * Professor of International Law, Department of Human and Social Sciences, University of Naples ‘L’Orientale’. 1 Corfu Channel Case (UK v Albania) (Merits) [1949] ICJ Rep 4. 2 Convention on the Territorial Sea and the Contiguous Zone (adopted 29 April 1958, entered into force 10 September 1964) 516 UNTS 205. QIL, Zoom-in 76 (2020) 5-19 6 QIL 76 (2020) 5-19 ZOOM IN In the final decades of the last century, however, the general exten- sion of territorial waters up to the twelve-mile limit produced a consid- erable multiplication in the number of straits within the territorial sea of coastal States. The complete submission to coastal sovereignty of about two thirds of the international straits was clearly leading to a progressive restriction of the areas subject to full freedom of navigation, which was replaced by the more limited right of innocent passage. Hence the recon- sideration of the matter at the Third Codification Conference on the Law of the Sea. Part III of the United Nations Convention on the Law of the Sea (UNCLOS)3 is specifically devoted to straits, with a clear intention to differentiate its discipline from Part II, devoted to the territorial sea. The regime of Part III is therefore a compromise solution, since the new ‘transit passage’ regime, which is much more favourable to States using straits than the non-suspendable innocent passage (downgraded to a rule valid for straits of minor importance), can be considered as a ‘compensa- tion’ demanded by the maritime powers in exchange for accepting the twelve-mile rule as the measure of maximum territorial sea extent. How is the transit passage different from the simple innocent pas- sage? Unlike the latter, transit passage also extends to overflight, and does not expressly require submarines to transit on the surface; therefore, there are fewer possibilities for the coastal State to limit navigation. This explains the resistance shown by many coastal States to the transit pas- sage regime both during the Third United Nations Conference on the Law of the Sea and after the entry into force of UNCLOS. In Europe, for example, Spain opposed the inclusion of the Strait of Gibraltar to this regime, as did Russia with regard to the straits in the Arctic Ocean, de- spite its policy of supporting the widest possible freedom of navigation, and despite the fact that the Soviet Union was a great supporter of this new regime at the time of the Third United Nations Conference on the Law of the Sea. According to Article 37 UNCLOS, the transit passage regime applies ‘to straits used for international navigation between one part of the high seas or Exclusive Economic Zone and another part of the high seas or Exclusive Economic Zone’. To other straits, in particular those which connect the high seas or the Exclusive Economic Zone (EEZ) with the 3 United Nations Convention on the Law of the Sea (adopted 10 December 1982, entered into force 16 November 1994) 1833 UNTS 397. The Strait of Hormuz 7 territorial sea of another State, the regime of innocent passage which can- not be suspended shall apply. However, Article 38 provides for an ex- ception to the regime of transit passage in the case of straits which, alt- hough connecting two parts of the high seas and/or the EEZ, are formed by an island belonging to a coastal State and its mainland, and ‘if there exists seaward of the island a route… of similar convenience with respect to navigational and hydrographical characteristics’. This exception is known as the ‘Messina clause’, because at the time of the Third Confer- ence on the Law of the Sea the Italian delegation supported it in order to take the Strait of Messina out of the limits set by the coastal State for cases of transit passage. However, the opinion of those who doubt that the alternative route, ie the circumnavigation of Sicily, is always ‘of simi- lar convenience’, does not seem to be groundless. Finally, Part III does not apply ‘to the legal regime in straits in which passage is regulated in whole or in part by long-standing international conventions in force specifically relating to such straits’ (Article 35, letter c). It is therefore without prejudice to what is specifically contained in treaties that refer to certain straits. But how to interpret the term ‘long- standing’? What is the ‘critical date’? This is not easy to determine. It is however clear that the provision refers to international conventions in a technical sense, such as the Montreux Convention of 1936 on the ‘Turk- ish Straits’, and not to communiqués and joint declarations of coastal States. It should be added that these agreements are currently showing signs of clear obsolescence, especially in the light of new environmental sensitivities, since the very liberal regime thereby envisaged, for example with regard to night-time passage, no longer seems justifiable given the large number of ships in transit with potentially dangerous cargo.4 As far as the obligations of the flag States of ships crossing straits are concerned, it is clear that the ships in question must refrain from any activity other than simple navigation, and that this must in any case take place continuously and expeditiously. Coastal States, for their part, have 4 On Part III, in general, cf M Fornari, Il regime giuridico degli stretti utilizzati per la navigazione internazionale (Giuffré 2010) 103 ff (see 521ff on the issue of coastal States requirements in order to prevent accidents dangerous for the environment); H Caminos, VP Cogliati-Bantz, The Legal Regime of Straits: Contemporary Challenges and Solutions (CUP 2014); D Caron, N Oral (eds), Navigating Straits: Challenges for International Law (Brill 2014); D Rothwell, ‘International Straits’, in D Rothwell and others (eds), The Ox- ford Handbook of the Law of the Sea (OUP 2015) 114 ff. 8 QIL 76 (2020) 5-19 ZOOM IN the right/duty to regulate transit, both to protect their legitimate interests and to ensure the safe passage of ships through straits. To this end, they may indicate the corridors of traffic and prescribe the necessary traffic separation schemes. Whether they can also make transit subject to prior notification or authorisation is a very sensitive issue, on which there was much discussion during the Third United Nations Conference on the Law of the Sea, particularly with regard to warships. Many coastal States insisted, even at the time of signature or ratification of UNCLOS, on de- positing interpretative declarations on the point, not only with regard to straits but also simply to the territorial sea, implying the offensive char- acter inherent in warships regardless of any activity. The final text of UNCLOS, however, implicitly recognizes warships as equal to merchant ships for the purpose of transit, as it does not contain any specific provi- sion on the passage of warships. But what indications does the practice offer us? As this writer has demonstrated in the past, the claims of the right to impose authorisation or notification for the transit of warships are merely petitions of principle. Beyond the regulations adopted, and looking only at what happens in practice, the common fact that emerges from the controversies some- times referred to as proof of the legitimacy of consent for the passage of warships is that in these cases the coastal State’s protests regarding the unauthorised transit of warships are part of a wider dispute. In such dis- pute, the main issue is not the question of consent for passage but, as the case may be, the fact that the ships in question did not limit their activities to mere transit, divergences as to the regime of the waters through which they passed, or other general political-diplomatic tensions, and so on. In other words, it is not possible to find any cases in which the legitimacy of the passage of foreign ships was challenged only for the breach of the rules of the coastal State requiring prior authorisation or notification for such passage.5 Passage is therefore granted to foreign warships also by those States which at the Third Conference, and in their domestic regu- lations, maintain the necessity of the requirement of prior authorisation or notification. One could not otherwise explain the absence of any dis- pute concerning the issue of mere unauthorised passage.