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.
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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.
5 On the point see G Cataldi, Il passaggio delle navi straniere nel mare territoriale (Giuffré 1990) 216 ff.
The Strait of Hormuz 9
The most recent practice, on the other hand, shows a growing ten- dency for coastal States to regulate transit for the protection of the marine environment, thus in the general interest of the international community, including through bans or notification requirements. For example, the adoption of mandatory pilotage systems for certain categories of ships to prevent the risk of accidents is widespread (see, for example, the ‘user manual’ for the Messina Strait). The issue here is different from the transit of warships, because of a general interest in environmental pro- tection, which is certainly not attributable only to the coastal State. We do not agree with the objections that some flag States of ships in transit raised against these initiatives, insofar as the latter are in line with a new concept of ‘freedom of the seas’, to be understood in a broader sense than in the past. There are also certain obligations and prohibitions which may appear prima facie unjustifiable from a legal point of view be- cause they are incompatible with the rule that passage in straits cannot be suspended, but which are reasonable in the light of the lack of appro- priate provisions for the protection of the marine environment in such areas.6
6 It is of interest to refer to two European Union documents on this subject: The Commission’s ‘Green Paper’: ‘Towards a future Maritime Policy for the Union: A European vision for the oceans and seas’ (COM (2006) 275 final, 7 June 2006), and Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for action by the Union in the field of maritime environmental policy. In particular, the ‘Green Paper’ clearly expresses the Commission's idea: ‘in order to meet the new challenges that arise, the legal system applicable to the seas and oceans based on the Montego Bay Convention needs to be improved. The provisions of the Convention relating to the EEZ and international straits limit the possibility for coastal States to exercise their jurisdiction over ships in transit, although any accidental pollution in these areas represents an immediate danger for these States, which, in fact, find it difficult to comply with their general obligation (also provided for in the Convention) to protect the marine environment from pollution’. These statements are, on the other hand, an acknowledgement of the practice. For example, two decrees of the Italian Minister of the Merchant Navy dated 27 March and 8 May 1985, still in force, prevent ships carrying more than ten thousand tons of oil products or other substances considered harmful to the marine environment from sailing in the Strait of Messina in the light of the international treaties in force for Italy. These measures were adopted after the collision in the Strait of Messina on 21 March 1985 between the Greek tanker Patmos and the Spanish tanker Castillo de Monte Aragon. Despite the U.S. diplomatic note of 5 April 1985 in which the legitimacy of the first Italian decree was challenged, we believe that these measures can be justified in the light of customary law, bearing in mind that the Strait, which connects two parts of the high seas, is less than two miles wide at its narrowest point. Also, on this matter, the agreement between Italy and France on the
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Over the centuries, the straits regime has been conditioned by politi- cal and military issues. The solution provided by UNCLOS to navigation in the straits has also seen strategic and military interests in maintaining important maritime routes open to navigation prevail over the interest in preserving and protecting the marine environment. Environmental con- cerns can certainly be added to the list of elements to be taken into ac- count when assessing the applicable regime. Straits are, in fact, water- courses which, by definition, are very limited in size but very frequently used. The risk of accidents such as collisions or spills of polluting material is higher than in open spaces. Transit is often made difficult due to geo- graphical and hydrographic characteristics. The effects of pollution caused by accidents can be devastating, especially in the case of ships such as oil tankers, nuclear-powered ships, ships carrying hazardous or noxious substances. It follows that, despite the interest of the States using them, the protection of the marine environment in straits must be con- sidered as the essential concern. From what has been said so far, we can deduce, in general, the fol- lowing: (1) The straits’ navigation regime as provided for in the UNCLOS – which is therefore compulsory for States which have ratified the Convention – distinguishes the right of passage which cannot be sus- pended from transit passage which is more favourable for vessels in nav- igation and is applicable to straits ‘used for international navigation’; this expression, in accordance with international case law, is to be interpreted restrictively, in the sense of excluding straits which are only ‘potentially suitable’ for international navigation but which are not currently used.7 (2) According to international practice, this rule is to be interpreted as not diversifying the regime for warships from the regime for merchant ships, since it is the activities and not the intrinsic nature of the ship that may constitute a threat to the coastal State and consequently make transit
Bonifacio Strait, which prohibits the transit of ‘dangerous’ ships flying the flag of these two States, should be mentioned. The content of this agreement has been endorsed by the IMO and incorporated into Recommendation A766 of 4 November 1993, which is addressed to all the Member States of the Organisation. 7 On this point, see M Fornari (n 4) 106. Even in light of the ICJ’s ruling in the Corfu Channel case, it does not appear possible to access the broad interpretation proposed by the U.S., according to which even straits which are potentially suitable but not currently used would fall into the category.
The Strait of Hormuz 11 offensive and therefore unlawful. (3) The exception to the rule just men- tioned concerns the passage of ships potentially dangerous to the environ- ment, because of the cargo carried or the propulsion mechanisms used; in the general interest of the international community, it is reasonable that the coastal State may require notification of the passage of such ships or more restrictive conditions for such passage, even to the point of prohibiting transit of particular categories of ships or in particular circumstances. So far, we have dealt with the issue of transit through straits from the viewpoint of the rules contained in UNCLOS and their interpretation in the light of practice. But what is the regime of straits ‘used for interna- tional navigation’ falling under the sovereignty of States which have not ratified UNCLOS, in particular with regard to the new concept of ‘transit passage’? Does ‘transit passage’ reflect customary law? In the following paragraphs we will try to provide answers to these controversial questions with specific reference to the Strait of Hormuz.
2. The Strait of Hormuz. Its legal regime according to Iran and Oman and according to the U.S.
The Strait of Hormuz, between 20 and 52 nautical miles wide, con- nects the Persian Gulf with the Gulf of Oman and the Indian Ocean. Its waters fall entirely under the sovereignty of two States: Iran and Oman. It is of considerable importance, since 88% of the oil extracted in the Gulf area, which accounts for 40% of all oil transported by sea, flows through its waters. Hence the risk of a global economic crisis and desta- bilisation of international relations if the coastal states the Strait tempo- rarily closed, as repeatedly threatened (as we shall see). This strait can also be considered as one of the most important points of encounter, and sometimes confrontation, between East and West, North and South, Sunnis, and Shiites. It is a strait that has certainly long been considered to be ‘used for international navigation’. However, tensions between its coastal States, in particular Iran, and the western States, first and fore- most the U.S., have persisted over its regime. It is clear that Iran’s ‘diffi- cult’ position in international relations plays a decisive role.8
8 In this regard, for a general reconstruction, see E Franckx, A Razavi, ‘The Strait of Hormuz’, in B Öztürk, R Özkan (eds), Proceedings of the Symposium on the Straits used
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First of all, Iran has always considered the management of the Strait of Hormuz as a strategic weapon in international politics. It must be said that even as early as the codification of Geneva Iran voted against the right of innocent passage through international straits, signing but never ratifying the 1958 Geneva Convention. Then, in 1959, giving raise to the protests of the United Kingdom and other States,9 it proceeded to extend its territorial sea to twelve miles, and with reference to the Strait of Hor- muz, citing security reasons as motivation. Iran is not even a Contracting Party to UNCLOS. A proposal by Iran at the Third United Nations Con- ference on the Law of the Sea calling for a special regime applicable to straits within semi-enclosed seas was rejected. At the time of signature this State filed an interpretative declaration in which it set out its position on the scope of the UNCLOS provisions. In particular, the ‘package deal’ character of many of these provisions was underlined, undoubtedly the result of a delicate balance of mutual concessions between developing and industrialised States interested in the recognition of maximum free- dom of navigation. Hence, again according to this declaration, the im- possibility to automatically consider these rules (with specific reference to the rules on transit passage and EEZ) as corresponding to customary law and thus also applicable to non-contracting States of UNCLOS, in accordance with Article 34 of the Vienna Convention on the Law of Trea- ties (1969 Vienna Convention).10 Furthermore, on that occasion Iran also affirmed that, in the light of customary international law, it considered as legitimate the requirement of authorisation for the passage of warships through the territorial sea, and thus the interpretation of Articles 19, 21 and 25 of UNCLOS to that effect.11 Obviously, this position provoked for International Navigation, 16-17 November 2002 (Turkish Marine Research Foundation 2002) 54 ff; F Caffio, ‘Lo Stretto di Hormuz’ (2008) Rivista marittima 29 ff. 9 On the Iranian Law of 12 April 1959 and the subsequent UK protest of 12 October 1959, see SH Amin, ‘The Regime of International Straits: Legal Implications for the Strait of Hormuz’ (1982) 12 J Maritime L and Commerce 387. 10 Vienna Convention on the Law of Treaties (adopted 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331. 11 This is the relevant part of the Declaration: ‘In accordance with article 310 of the Convention on the Law of the Sea, the Government of the Islamic Republic of Iran seizes the opportunity at this solemn moment of signing the Convention, to place on the records its “understanding” in relation to certain provisions of the Convention. The main objec- tive for submitting these declarations is the avoidance of eventual future interpretation of the following articles in a manner incompatible with the original intention and previous positions or in disharmony with national laws and regulations of the Islamic Republic of
The Strait of Hormuz 13 negative reactions from Western countries, as well as the subsequent adoption, in 1993, of a law on marine areas, still in force today, which provides for prior authorisation for the passage into the territorial sea of numerous categories of ships, including warships.12 Iran, therefore, even after the extension of its territorial waters to twelve miles, claims the application of the regime of non-suspendable right of innocent passage in the Strait of Hormuz, rather than transit pas- sage, with the burden, for warships, of the need to obtain prior authori- sation for passage. This implies only a partial acceptance of the Law of the Sea developments, since the extension to twelve miles of the territo- rial sea has become established in customary law (and in UNCLOS) pre- cisely because of that ‘package deal’ that Iran rejects, ie as a consequence of the acceptance of this measure also by the Maritime Powers willing to adhere to it in exchange for guarantees and concessions such as, for ex- ample, passage in transit. It could even be argued that, by setting aside
Iran. It is the understanding of the Islamic Republic of Iran that: 1) Notwithstanding the intended character of the Convention being one of general application and of law making nature, certain of its provisions are merely product of quid pro quo which do not neces- sarily purport to codify the existing customs or established usage (practice) regarded as having an obligatory character. Therefore, it seems natural and in harmony with article 34 of the 1969 Vienna Convention on the Law of Treaties, that only states parties to the Law of the Sea Convention shall be entitled to benefit from the contractual rights created therein. The above considerations pertain specifically (but not exclusively) to the follow- ing: - The right of Transit passage through straits used for international navigation (Part III, Section 2, Article 38). - The notion of “Exclusive Economic Zone” (Part V). - All matters regarding the International Seabed Area and the Concept of ‘Common Heritage of mankind’ (Part XI). 2) In the light of customary international law, the provisions of Article 21, read in association with Article 19 (on the Meaning of Innocent Passage) and Article 25 (on the Rights of Protection of the Coastal States), recognize (though implic- itly) the rights of the Coastal States to take measures to safeguard their security interests including the adoption of laws and regulations regarding, inter alia, the requirements of prior authorization for warships willing to exercise the right of innocent passage through the territorial sea’. 12 Several protest notes were issued by the U.S. More nuanced is the European Union note presented by Germany in 1994 which ‘takes note’ of the Iranian decision. On those occasions the wording of art 6 of the Law was also challenged, insofar far as it considered the passage as offensive if the ships took information prejudicial to Iran’s economic interests, a case which is not envisaged by art 19(2) UNCLOS, which refers only to acts contrary to the Convention. In this respect, see S Bagheri, ‘Iran’s Attitude to Security in the Strait of Hormuz: An International Law Perspective’ (2015) 13 New Zealand YB Intl L 83.
14 QIL 76 (2020) 5-19 ZOOM IN the ‘package deal’, this would result in the possibility of reviving full free- dom of navigation beyond three miles in the relations between States that have not ratified UNCLOS. In fact, it has been argued that the extension of the territorial sea to twelve miles is inseparable from the recognition of the right of passage in transit through straits, ie automatically requiring acceptance.13 We are only partially in agreement with the latter position, since in our opinion the regime to be considered in conformity with gen- eral international law is halfway between this extreme position and the Iranian claims, as we will shortly try to demonstrate. Unlike Iran, Oman ratified UNCLOS on 17 August 1989. This cir- cumstance makes the claim of Oman not to be bound by the transit re- gime even weaker than the one of Iran.14 When signing and ratifying the Convention, Oman declared that the UNCLOS provisions on the right of innocent passage and transit passage do not prevent a coastal State from taking the necessary measures to protect its interests in peace and security, in particular the possibility of requiring prior permission for warships crossing its territorial sea, including the waters of the Straits of Hormuz. As a matter of fact, its legislation on the issue (a royal decree of 1981) which did not recognise the right of passage in transit either for ships or aircraft was not amended following the ratification of UNCLOS; on the contrary, the declaration mentioned above specifically indicated the obligation of prior authorisation for warships. Therefore, even if with some differences, and with some mutual di- vergence (eg Iran protested when Oman established a system of straight lines in its territorial sea), the position of the two coastal states regarding the regime to which the Strait of Hormuz is subject is essentially the same as regards the main aspects, ie the idea that the extension of the territorial sea to twelve miles has not changed the status of the Strait, which is still subject to the rule of the right of innocent passage and the need for au- thorisation for the transit of military ships. These are the official positions of the two coastal states. It is now nec- essary to consider whether the domestic legislation adopted and the dec- larations deposited at international level correspond to practice, ie the degree of their effective application. We believe this to be crucial in order
13 This seems to be the opinion of J Kraska, ‘Legal Vortex in the Strait of Hormuz’ (2014) 54 Virginia J Intl L 323, 364 ff. 14 On this point see the article by Franckx, Razavi (n 8) 61.
The Strait of Hormuz 15 to verify what customary law prescribes in this area. Although the prac- tice to which reference should be made is mainly that of peacetime, bear- ing in mind that UNCLOS does not apply in times of war, it should be remembered that during the Iran/Iraq conflict the Strait of Hormuz was part of a larger war zone and ships in transit, including merchant ships, were subject to attacks by both sides, considered universally illegal.15 Sig- nificant for our purposes is the fact that Iran closed its coasts at the be- ginning of the war, but always left the Strait of Hormuz open to transit. Certain conditions were imposed, for example navigation only during the day and with compulsory pilotage, and 48 hours notice for the transit of oil tankers. With the worsening of the conflict, detentions and inspec- tions were carried out based on the suspicion of transporting weapons to the enemy. But all this seems to correspond to the security requirements admitted as legitimate by customary law, especially with reference to the practice of the Second World War.16 Particularly useful for the identification of the applicable customary regime appears to be the detection of the practice related to Iran’s rela- tions with the United States, both because of the conflict that for many years has seen the two States opposing each other, and because the United States also has yet to ratify UNCLOS. The official position of the U.S. Government, which has long been supported, in particular through the FON (1979 Freedom of Navigation Program),17 is that: (a) Iran may control the passage through the Strait of
15 As it is well known, on 20 July 1987 the UN Security Council adopted resolution 598 (1987) condemning attacks on merchant ships. Iran also proceeded with the laying of mines in the Strait, an action universally qualified as illegal because it was detrimental to the international navigation of neutral States. In response to an incident involving one of its warships, the U.S. launched the Operation ‘Praying Mantis’ on 18 April 1988, attacking Iran’s oil platforms in its territorial sea. This action was qualified by the ICJ in its ruling of 6 November 2003 (Oil Platforms Case, Islamic Republic of Iran v United States of America (Judgment) [2003] ICJ Rep 161 ff) as an illegitimate countermeasure, since the incidents that occurred could not be defined as an armed attack on the U.S. (see Bagheri (n 12) 92; N Oral, ‘Transit Passage Rights in the Strait of Hormuz and Iran’s Threats to Block the Passage of Oil Tankers’ (2012) 16 ASIL Insights
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Hormuz but may not close or block it, and, as a signatory of UNCLOS, may not act contrary to the purposes and object of that Convention, in light of the rules of treaty law codified by the 1969 Vienna Convention; (b) the right of transit passage is also provided for by customary law, since it reflects an established practice and corresponds to the opinio iuris of the majority of States. The possible closure of the Strait, the prohibition of overflight and the obligation for submarines to transit in emergence would therefore always be unjustified and illegitimate, since it is contrary to the right of transit passage as provided by customary law as codified by UNCLOS. The right of the coastal State to prevent transit would re- main limited only to the case of ships threatening or using force against the sovereignty, political independence, territorial integrity of coastal States, or otherwise in violation of the principles of international law in- corporated in the UN Charter. Moreover, according to the U.S.’ position, no distinction could be made between merchant and military vessels, since it is the behaviour and not the nature of the ship that is decisive.
3. Conclusions. The legal regime of the Strait of Hormuz under customary law
The examination of the practice of transit through the Strait of Hor- muz confirms what has already been observed in general regarding pas- sage through territorial waters, ie that the internal regulatory provisions which provide for the possibility of closure of the Strait for safety reasons and which impose the obligation of authorisation for the transit of mili- tary vessels do not receive effective and concrete implementation, unless a situation of latent or declared conflict already exists between the coastal State and the flag State of the vessel in question. These provisions serve to be excessive – that is, such claims are inconsistent with the international law of the sea and impinge upon the rights, freedoms, and uses of the sea and airspace guaranteed to all states under that body of international law. The United States, however, ‘will not […] acquiesce in unilateral acts of other states designed to restrict the rights and freedom of the international community’. Since 1979, U.S. Presidents have directed the U.S. Government to carry out a Freedom of Navigation (FON) Program to preserve this national interest and demonstrate a non-acquiescence to excessive maritime claims asserted by coastal states. The U.S. FON Program includes: (1) consultations and representations by U.S. diplomats (ie, U.S. Department of State), and (2) operational activities by U.S. military forces (ie, U.S. Department of Defense (DoD) FON Program).
The Strait of Hormuz 17 as exceptional measures to be activated in case of need. The practice of the 1990 Gulf War is enlightening in this respect: warships from the U.S. and other countries engaged in the conflict crossed the Strait of Hormuz several times without authorisation, and without arising any specific re- action from the two coastal States.18 Likewise, despite repeated threats,19 the Iranian government never proceeded to close the Strait in reaction to the economic sanctions adopted by the international community against it. Only in a few isolated cases have there been initiatives to prevent navigation directly linked to another specific event. The latter circumstance was however constantly and explicitly denied and these initiatives were justified with the assertion of violation of internal rules. This shows Iran’s awareness that such an action could not be justified as a countermeasure. A recent example is the case of the British tanker ‘Stena Impero’, which was blocked in the port of Bandar Abbas from 20 July to 23 September 2019 due to unspec- ified violations of ‘international maritime laws’ and internal navigation regulations. Despite the contrary statements of the ‘Teheran Revolution- ary Guard Corps’, this initiative was a clear response to the blockade of the Iranian tanker ‘Grace 1’ (also known as ‘Adrian Darya’) off Gibraltar, which took place on 4 July 2019 on the suspicion of having violated the sanctions imposed by the European Union for transferring oil to Syria. ‘Grace 1’ was finally allowed to set sail on 19 August.20 It is clear that the enforcement of sanctions decreed by the United Nations cannot justify reactions such as interference in navigation across the Straits, whether it is qualified as a transit passage under UNCLOS or as an exercise of the right of passage that cannot be suspended under the 1958 Convention. But even if a unilateral attack against Iranian nuclear installations without the authorisation of the Security Council were to be launched illegally,
18 On this point see the practice referred to by Bagheri (n 12) 91 ff. 19 See in particular December 2011 Statement of Iran First Vice-President, quoted in M Wählisch, ‘The Iran-US Dispute, the Strait of Hormuz, and International Law’ (2012) 37 Yale J Intl L Online 22. For other examples see also Oral (n 15). 20 The story is widely described and commented on the internet. See for example
18 QIL 76 (2020) 5-19 ZOOM IN the application of the well-known criteria of necessity and proportional- ity would not justify an Iranian countermeasure to close the Strait.21 In conclusion, there is no doubt that the general rule that the passage of ships cannot be suspended in straits also applies to the Strait of Hor- muz. This rule applies to warships as well as to merchant vessels, and no authorisation or notification of passage can be demanded in advance by the coastal State as a mandatory requirement for transit, since it is the activity and not the type of vessel that is decisive. Parenthetically, the specific practice of navigation through this Strait confirms the general rule. Therefore, the non-suspendable right of passage as provided by cus- tomary law and codified in the 1958 Geneva Convention applies to the Strait of Hormuz. It is more difficult, in our opinion, to argue that the right of transit passage governed by UNCLOS may apply to the Strait of Hormuz. In- deed, a certain weight must be given to the fact that Iran and Oman op- posed this new discipline from the very first moment, as did other coastal states of important straits (Turkey, Venezuela) which, like Iran, did not ratify UNCLOS. It should be remembered that, as stated by the ICJ in its 1969 ruling on the delimitation of the North Sea continental shelf, the position of the States directly concerned by the application of the regime provided for by a rule has a different and more relevant value in ascer- taining the customary value of the rule itself.22 In short, also in the light of the ambiguous attitude of many States (Spain, Russia) already re- ported, which, even though they have ratified UNCLOS, find it difficult to recognize the validity of this institution with respect to the straits un- der their sovereignty, in many cases maintaining in force laws adopted prior to the ratification of UNCLOS, which in fact deny the right of transit (in accordance with the ‘not in my backyard’ rule), it does not
21 This aspect, linked to the issue of internationally wrongful acts, would deserve to be discussed in depth elsewhere. See, however, the considerations of D Guilfoyle, ‘Iran and the Strait of Hormuz: Some initial Thoughts’ (2012) EJIL Talks
The Strait of Hormuz 19 seem sustainable to us that the regime provided for in the UNCLOS cor- responds to customary law. Therefore, its application cannot be claimed outside the circle of States that have ratified the Convention. It is para- doxical that the most strenuous defender of the customary value of the right of transit established by UNCLOS is the U.S., which has not ratified the Convention and is a party to the 1958 Geneva Convention (which does not provide for this right!). However, the problem of passage through the Strait of Hormuz can be greatly reduced and solved from a practical point of view since, as has been pointed out,23 the most convenient sea routes for navigation pass through the territorial sea of Oman. Therefore, it is very unlikely that warships and merchant ships entering or leaving the Gulf navigate in the territorial sea of Iran which, as has been seen, represents the sea route posing the greatest difficulties.
23 Fornari (n 4) 245.