(a) Customary Law
The right of innocent passage of warships is of paramount importance for major naval
powers in order to secure global naval mobility. However, the passage of foreign warships
through the territorial sea may be a threat to the security of the coastal State. A difficult
question thus arises as to whether or not foreign warships have the right of innocent
passage in international law. In this respect, Article 5 of the Resolution adopted by the
Institut de droit international at its 1894 Paris session stated that all ships without distinction
have the right of innocent passage through the territorial sea. On the other hand,
Article 11 of the Resolution adopted by the Institut at its 1928 Stockholm session stated that
the free passage of foreign warships may be subject to special rules of the riparian State.
In 1929, ‘Research in International Law’ by Harvard Law School also stated: ‘The sovereignty
of the littoral state is restricted by the right of innocent passage because of a
recognition of the freedom of the seas for the commerce of all states. There is, therefore,
no reason for freedom of innocent passage of vessels of war.’
At the 1930 Hague Codification Conference, Articles 12 and 13 of the Legal Status of
the Territorial Sea, attached to the Report Adopted by the Committee on 10 April 1930,
stated:
As a general rule, a coastal State will not forbid the passage of foreign warships in its territorial
sea and will not require a previous authorisation or notification. The coastal State has the right
to regulate the conditions of such passage. Submarines shall navigate on the surface.
If a foreign warship passing through the territorial sea does not comply with the regulations
of the coastal State and disregards any request for compliance which may be brought to its
notice, the coastal State may require the warship to leave the territorial sea.
In view of those provisions, Gidel argued that the passage of foreign warships through the
territorial sea is not a right, but a tolerance (tolérance) of the coastal State.
Later, the right of innocent passage of foreign warships was at issue in the 1949 Corfu
Channel case between the United Kingdom and Albania. In this case, Albania asserted that
it could regulate the passage of foreign warships in Albanian territorial waters. By contrast,
the United Kingdom maintained that warships possess a right of innocent passage through
the territorial sea of another State. While the ICJ accepted the right of innocent passage of foreign warships in straits used for international navigation, it did not directly address the
question of whether foreign warships have the same right of innocent passage in the
territorial sea. Overall it may have to be accepted that customary international law is
obscure on this subject.
(b) Treaty law
The TSC contains no provision relating to the right of innocent passage of foreign warships.
However, Article 14(1) of the TSC stipulates:
Subject to the provisions of these articles, ships of all States, whether coastal or not, shall enjoy
the right of innocent passage through the territorial sea.
It must be noted that this provision is under the rubric ‘Rules Applicable to All Ships’.
Further, Article 14(2) sets out that submarines are required to navigate on the surface, when
in the territorial sea, and to show their flag. It can be presumed that this provision relates
specifically, if not totally, to military submarines. Moreover, in UNCLOS I, a draft provision
which was intended to allow the coastal State to make the passage of warships through the
territorial sea subject to previous authorisation or notification was not adopted. In
addition, Article 23 provides that if a warship fails to comply with the regulations of the
coastal State concerning passage through the territorial sea, the coastal State may require
the warship to leave the territorial sea. Noting these points, some argue that warships have a
right of innocent passage under the TSC.
In common with the TSC, the LOSC contains no explicit provision with respect to the
right of innocent passage of foreign warships in the territorial sea. However, four points
must be noted.
First, like Article 14(1) of the TSC, Article 17 of the LOSC, which provides the right of
innocent passage, is under the rubric ‘Rules Applicable to All Ships’. It can be presumed,
therefore, that Article 17 is applicable to all ships, including warships.
Second, as with Article 14(2) of the TSC, Article 20 of the LOSC requires submarines and
other underwater vehicles to navigate on the surface and to show their flag in the
territorial sea.
Third, as has been seen, Article 19(2) sets out a catalogue of activities which render
passage non-innocent. Some of these activities, such as any exercise or practice with
weapons, the take-off or landing of aircraft, and the launching or receiving of any military
device, relate specifically, if not totally, to warships.
Overall, those provisions seem to hint at the right of innocent passage of foreign
warships. This interpretation seems to be supported by writers, such as Brown, Carlos
Espaliú Berdud, Churchill, Dupuy/Vignes, Johnson, Keyuan, Lucchini/Voelckel, Rothwell/
Stephens, Treves and Vincent.
(c) State Practice
State practice is not uniform on this subject. In ratifying the LOSC, some States – for
example, Germany and the Netherlands – explicitly declared that the Convention permits
innocent passage in the territorial sea for all ships, including foreign warships. Thailand has
also taken the position that all foreign ships, including warships, can exercise the right of
innocent passage in the territorial sea. Of particular importance is the 1989 Uniform
Interpretation of Norms of International Law Governing Innocent Passage between the
United States and the USSR. Paragraph 2 of this bilateral document states:
All ships, including warships, regardless of cargo, armament or means of propulsion, enjoy the
right of innocent passage through the territorial sea in accordance with international law, for
which neither prior notification nor authorisation is required.
While, at UNCLOS I, the USSR took the position that the passage of foreign warships
through a territorial sea required prior authorisation, the USSR had become a leading naval
power by the end of the 1960s and early 1970s. Consequently, the USSR changed its policy
in order to ensure the maximum freedom of navigation of warships.
However, nearly forty States, mainly developing States, require prior notification or
prior authorisation of the passage of warships through their territorial sea. In
ratifying the LOSC, however, some States – Germany, Italy, the Netherlands and the
United Kingdom – expressed the view that claims to prior authorisation and prior notification
were at variance with the LOSC. The United States has also protested against most of
the claims to both prior authorisation and prior notification. A question thus arises of
whether prior notification or prior authorisation is compatible with the LOSC.
When considering this issue, a distinction must be drawn between the requirement of
prior notification and that of prior authorisation. There appears to be scope to argue that the
requirement of prior notification could fall within the scope of Article 21(1)(a) of the LOSC.
If this is the case, the right of innocent passage of foreign warships and the requirement of
prior notification of the coastal State could be compatible. However, it appears that the
legality of prior authorisation remains a matter for discussion.
Coastal State action against foreign warships is qualified by the sovereign immunity
afforded to warships. However, the coastal State may require any warship to leave its
territorial sea if the warship does not comply with the laws and regulations of the coastal
State pursuant to Article 30 of the LOSC. Under Article 31, the flag State is also obliged to
bear international responsibility for any loss or damage to the coastal State resulting from
the non-compliance by a warship or other governmental ship operated for noncommercial
purposes with the laws and regulations of the coastal State concerning
passage through the territorial sea or with the provisions of the LOSC or other rules of
international law.
(d) The Right to Render Assistance to Persons in Distress
A further question is whether a foreign warship has a right to enter into the territorial sea of
another State to render assistance to persons in distress, without prior notification to the
coastal State. Article 98 of the LOSC, which applies to the high seas and the EEZ, places an
explicit obligation upon every State to render assistance to any person found at sea in
danger of being lost. While the LOSC contains no duty to render assistance to any persons
in distress in the territorial sea, the offer of such assistance would be consistent with the
requirement of the consideration of humanity. Indeed, a temporary entrance of a foreign
warship into the territorial sea for the purpose of rendering assistance to persons in distress
would pose no threat to the coastal State. Hence there may be room for the view that a
foreign warship can render assistance to persons in distress in the territorial sea without
notification to the coastal State.