Legal Framework for International Straits Prior to 1982
In light of the paramount importance of international straits for sea communication, the freedom of navigation through straits has attracted much attention in the international community. A question is whether or not foreign vessels enjoy the right of innocent passage through international straits between one part of the high seas and another under customary law. The ICJ, in the 1949 Corfu Channel case, gave a positive answer to this question, by stating:
It is, in the opinion of the Court, generally recognized and in accordance with international custom that States in time of peace have a right to send their warships through straits used for international navigation between two parts of the high seas without the previous authorization of a coastal State, provided that the passage is innocent. Unless otherwise prescribed in an international convention, there is no right for a coastal State to prohibit such passage through straits in time of peace.
Reflecting the dictum in the Corfu Channel judgment, Article 16(4) of the TSC provided:
There shall be no suspension of the innocent passage of foreign ships through straits which are used for international navigation between one part of the high seas and another part of the high seas or the territorial sea of a foreign State.
As this provision relates to the right of innocent passage in the territorial sea, it is clear that the right does not comprise the freedom of overflight. On the other hand, unlike the right of innocent passage through the territorial sea in general, the exercise of the right through international straits shall not be suspended. To this extent, the right of innocent passage through international straits is more strengthened than the right of innocent passage through the territorial sea in general. In light of the Corfu Channel judgment, it seems that foreign warships also possess the right of non-suspendable innocent passage set out in Article 16(4).
As noted earlier, the Corfu Channel judgment referred only to straits ‘between two parts of the high seas’. By referring to straits ‘between one part of the high seas and another part of the high seas or the territorial sea of a foreign State’, however, Article 16(4) extended the scope of straits. Thus it may be said that Article 16(4) is a result of the development of customary law, not simple codification of the law.
Typology of International Straits Under the LOSC
According to a survey, there are 52 international straits less than 6 nautical miles in width, international straits between 6 and 24 nautical miles in width, and 60 international straits more than 24 nautical miles in width. By establishing the 12-mile territorial sea, many straits which include a strip of high seas fall within the territorial sea of the coastal States. The ‘territorialisation’ of international straits would compromise the freedom of overflight of (military) aircraft and navigation of foreign warships, including submerged submarines. Thus maritime States urged the introduction of a new regime relating to the right of ‘transit passage’, which was finally embodied in Part III of the LOSC. It is important to note that the agreement on the 12-mile territorial sea was closely linked to ensuring the freedom of navigation and overflight through international straits. The Convention divides international straits into two main rubrics according to the applicability of Part III, namely, straits to which Part III applies and straits outside the scope of Part III.
International Straits Under Part III of the LOSC
First, we shall examine straits where Part III applies. In this regard, it must be noted that Part III does not affect any areas of internal waters within a strait, except where the establishment of a straight baseline in accordance with the method set forth in Article 7 has the effect of enclosing as internal waters areas which had not previously been considered as such. It
would seem to follow that basically Part III applies to international straits as the territorial sea. The straits under Part III of the LOSC contain two types of straits: straits to which the regime of transit passage applies and straits to which the right of innocent passage applies.
The first type concerns straits to which the regime of transit passage applies. In this regard, Article 37 provides:
This section applies to straits which are used for international navigation between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone. This provision contains two criteria for identifying international straits under Part III.
The first is the geographical criterion. Such straits are those connecting ‘one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone’. The second is the functional criterion, namely ‘straits used for international navigation’. Concerning the relationship between the two criteria, the ICJ, in the Corfu Channel case, seemed to consider that the geographical criterion provided the primary criterion. In the words of the Court:
It may be asked whether the test is to be found in the volume of traffic passing through the Strait or in its greater or lesser importance for international navigation. But in the opinion of the Court the decisive criterion is rather its geographical situation as connecting two parts of the high seas and the fact of this being used for international navigation.
The functional criterion raises an issue as to how it is possible to identify ‘straits used for international navigation’. In this regard, it is argued that a strait must actually be used for international navigation as a useful route for international maritime traffic in order to meet the functional criterion. Mere potential utility would be insufficient.
As will be seen, transit passage applies to the strait between one part of the high seas or an EEZ and another part of the high seas or an EEZ in accordance with Article 38(1). An example of international straits to which the regime of transit passage applies may be provided by the Dover Strait. In some cases, a question arises of whether or not a strait can be considered as a ‘transit passage’ strait. One might take the Canadian Northwest Passage through Canada’s Arctic archipelago as an example. This passage is a series of connected straits that weave through the maritime features which constitute the Canadian Arctic Archipelago.
Recently, growing attention has been paid to the Northwest Passage because the presumed decline in sea ice in the Arctic Ocean may open a navigational route connecting the Atlantic and the Pacific through the Northwest Passage. In 1985, Canada drew straight baselines around its Arctic archipelago and, consequently, the Northwest Passage fell within Canada’s internal waters. Canada thus rejected ‘any suggestion that the Northwest Passage is such an international strait’. However, the United States has taken the position that the Passage is a strait used for international navigation subject to the transit passage regime. The disagreement was circumscribed by the 1988 Agreement on Arctic Cooperation between Canada and the United States. In this Agreement, the United States and Canada agreed to ‘undertake to facilitate navigation by their icebreakers in their respective Arctic waters and to develop cooperative procedures for this purpose’. The Agreement also maintains the position of both parties by providing in Article 4 that:
Nothing in this agreement of cooperative endeavour between Arctic neighbours and friends nor any practice thereunder affects the respective positions of the Governments of the United States and of Canada on the Law of the Sea in this or other maritime areas or their respective positions regarding third parties.
A similar question arises with regard to the legal status of the Northeast Passage, north of Russia. By decree of 15 January 1985 the Soviet Union established straight baselines in the Arctic Ocean. As a consequence, major straits which may be portions of the Northeast Passage or the Northern Sea Route became part of Russian internal waters. Nonetheless, the United States asserted that the Northern Sea Route constitutes international straits. In light of the relatively limited usage of foreign-flagged vessels passing through these straits, however, some doubts were expressed by writers regarding whether the straits can be considered as those ‘used for international navigation’ where the right of transit passage applies. In any case the Russian Federation adopted a series of national legislations concerning the Northern Sea Route, such as the Federal Law of 28 July 2012 and Rules of Navigation in the Water Area of the Northern Sea Route. In particular, the 2013 Rules of Navigation sets out the procedure for obtaining permission to navigate the Northern Sea Route.
In addition to this, some mention should be made of the Straits of Malacca and Singapore. Traffic transiting the Straits of Malacca and Singapore is heavy because they form one of the world’s major choke points for international trade and commerce. The Joint Statement of the Governments of Indonesia, Malaysia and Singapore of 16 November 1971 stated that ‘the Straits of Malacca and Singapore are not international straits while fully recognising their use for international shipping in accordance with the principle of innocent passage’. Later, however, these three States became parties to the LOSC. As a consequence, one can say that transit passage presently applies to the Straits of Malacca and Singapore in accordance with relevant provisions of the Convention.
A second type relates to straits to which the right of innocent passage applies. Such straits include:
• straits which are excluded from the application of the regime of transit passage under Article 38(1) of the LOSC, and
• straits between a part of the high seas or an EEZ and the territorial sea of a foreign State. ‘Straits which are excluded from Article 38(1)’ are straits formed by an island of a State bordering the strait and its mainland, and there exists seaward of the island a route through the high seas or through an EEZ of similar convenience with respect to navigational and hydrographical characteristics. A good example is the Messina Strait. Examples of ‘straits between a part of the high seas or an EEZ and the territorial sea of a foreign State’ are the Tiran Strait and the Gulf of Aquaba.
International Straits Outside the Scope of Part III of the LOSC
The second rubric concerns straits to which Part III of the LOSC does not apply. Three types of straits are included in the rubric.
First, under Article 36 of the LOSC, Part III does not apply to straits used for international navigation which contain a route through the high seas or through an EEZ of similar convenience with respect to navigational and hydrographical characteristics. Article 36 appears to imply that if a route through the high seas or through an EEZ in the international strait is not convenient with respect to navigational and hydrographic characteristics, Part III will apply to the territorial sea within the strait. In relation to this, it is interesting to note that Japan has limited its territorial sea claim in five international straits, namely the Soya Strait, the Tsugaru Strait, the Tsushima Eastern Channel, the Tsushima Western Channel and the Osumi Strait, creating a corridor of the EEZ in the middle of these straits. As a result, these five straits pertain to a strait ‘which contains a route through an EEZ of similar convenience’ under Article 36 of the LOSC.
Second, Part III does not apply to straits in which passage is regulated in whole or in part by long-standing international conventions in force specifically relating to such straits pursuant to Article 35(c) (type B-2). While the LOSC does not specify the straits to which Article 35(c) applies, examples may be briefly summarised as follows:
(i) The Turkish Straits: these straits include the Dardanelles, the Sea of Marmara, and the Bosphorus, which connect the Black Sea and the Aegean Sea. The Turkish Straits are governed by the 1936 Convention Regarding the Régime of the Straits (Montreux Convention).The Convention contains a set of special rules for, inter alia, the free passage of warships, merchant vessels and authorisation for civil aviation.
(ii) The Danish Belts and the Sound: these straits comprise the Little Belt between Jutland and the island of Funen, the Great Belt between Funen and the island of Zealand, and the Öresund Sound between Zealand and Sweden. These straits are regulated by the Treaty for the Redemption of the Sound Dues between Denmark and European States of 14 March 1857 (the Treaty of Copenhagen). Article I of the Convention provides for a right of passage of foreign ships through the Danish straits, by stating: ‘No vessel shall henceforth, under any pretext whatsoever, be subject in its passage of the Sound or the Belts to any detention or hindrance.’ The rights provided in the Copenhagen Treaty were accorded to
ships of all States, including ships from third States.
(iii) The Strait of Magellan: the Strait between Argentina and Chile connects the Pacific and the Atlantic Oceans. Article 5 of the 1881 Treaty between Argentina and Chile confirmed the neutralisation of the Strait of Magellan and free navigation to the flags of all nations. This was confirmed by Article 10 of the 1984 Treaty of Peace and Friendship
between Argentina and Chile.
(iv) The Strait of Gibraltar: this strait joints the Mediterranean Sea and the Atlantic Ocean. The free passage of the Strait of Gibraltar was declared in the 1904 Anglo-French Declaration (Article 7), and was confirmed by Article 6 of the 1912 Treaty between France and Spain regarding Morocco.
(v) The Åland Strait: upon signing the LOSC, Finland and Sweden declared that Article 35(c) of the Convention is applicable to the strait between Finland (the Åland Islands) and Sweden. The applicable treaties are the 1921 Convention on the Non-Fortification and Neutrality of the Åland Islands and the 1940 Agreement between Finland and the Soviet
Union concerning the Åland Islands, which obliged Finland to demilitarise the Åland Islands and not to fortify them.
The third category of straits to which Part III does not apply involves international straits within archipelagic waters. Navigation in the archipelagic waters will be examined in section 5 of this chapter.