Helga Law Journal - 01.01.2021, Qupperneq 67

Helga Law Journal Vol. 1, 2021
68
Dr. Snjólaug Árnadóttir
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declaration of a State […] the other State or States concerned may incur obligations
in relation to such a unilateral declaration to the extent that they clearly accepted
such a declaration’.
States generally have a legal interest in making sure that maritime limits of
other States satisfy the requirements of UNCLOS. Even if they have no
overlapping claims to maritime zones, they may have legitimate interests relating
to claims encroaching upon the high seas or the international seabed area.97 On
the other hand, it is in the interest of coastal States to push their maritime limits
seaward and some States have gone to great lengths to further their maritime
entitlements. For example, ‘almost all of the States of the Asia-Pacific region have
adopted straight baseline systems that are inconsistent with international law’ and
they maintain these claims despite vigorous opposition.98 The ILA Baselines
Committee identified 82 protests or objections to straight baselines. These
challenges have been submitted by 21 States and the EU and lodged against 39
States, covering almost 50% of all straight baseline claims.99 The United States has
actively objected to the unlawful use of baselines worldwide and other States have
made similar efforts.100 These objections can prevent acquiescence because, if
successfully challenged, unlawful maritime limits become invalid vis-à-vis other
States.101
If States fail to challenge excessive maritime limits, they may later be estopped
from challenging such limits. As explained by Churchill and Lowe:
Where a baseline is clearly contrary to international law, it will not be
valid, certainly in respect of States which have objected to it, though a
State which has accepted the baseline (for example in a boundary treaty)
might be stopped from later denying its validity. In border-line cases—
for example, where there is doubt as to whether a State’s straight baseline
system conforms to all the criteria laid down in customary and
conventional law—the attitude of other States in acquiescing in or
objecting to the baseline is likely to prove crucial in determining its
validity.102
The submission of charts, or lists of geographic coordinates, to the UNSG is
crucial for the formation of acquiescence and estoppel because it provides States
with the information necessary to raise their objections. The ICJ has indicated that
challenges should generally be raised shortly after submission of data to the

97 See, e.g., Chagos Marine Protected Area (Mauritius v United Kingdom) (2015) XXXI RIAA 359, para 153;
Anglo-Norwegian Fisheries (n 35) 125.
98 Ashley Roach and Robert W Smith (n 57) 66.
99 ILA Baselines Committee, ‘Johannesburg Conference’ (ILA 2016) 17, para 65.
100 Ashley Roach and Robert W Smith (n 57) 48.
101 See, e.g., South China Sea (n 7) paras 278 and 1203 B.(2).
102 Robin R Churchill and Alan V Lowe, The Law of the Sea, 2nd revised edition (Manchester University
Press 1988) 46-47.
The ILC has published ‘Guiding Principles applicable to unilateral
declarations of States capable of creating legal obligations’.87 The principles deal
with declarations ‘formulated by States in exercise of their freedom to act on the
international plane’ and not on ‘unilateral acts […] formulated in the framework
and on the basis of an express authorization under international law’.88 Thus, the
principles are not directly applicable to maritime limits established in accordance
with UNCLOS but the ILC’s commentary and preparatory work is of relevance
for this discussion, particularly to limits that become inconsistent with the law due
to environmental changes. According to Guiding Principle 3, the legal effects of
unilateral declarations depend inter alia on the reactions they invoke.89 When
preparing this Guiding Principle, the ILC referenced the 1945 Truman
proclamation,90 whereby the United States established unilateral limits to the
continental shelf. This occurred before the conclusion of a framework treaty
(UNCLOS and the Convention on the Continental Shelf).91 Yet, the declaration
soon became opposable because of the positive reactions it received from other
States.92 As noted by the ICJ, the Truman proclamation is a ‘particular source that
has secured a general following’.93
The ILC also explained how objections could prevent tacit acceptance of
maritime limits and referenced the following example. Turkmenistan established
baselines and territorial sea limits in 1993 and Russia protested these limits in
January 1994 by means of a diplomatic note, stating that this unilateral action
would not be recognised by Russia.94 According to the ILC, these protests were
‘necessary to prevent a situation whereby silence on the part of the Russian
Federation could be invoked against it in the future as a tacit acceptance of or
acquiescence in the claims of Turkmenistan’.95 Indeed, failure to object to
potentially unlawful maritime limits can amount to acquiescence or tacit
acceptance.96 Such failure can give unilateral maritime claims binding force,
whereas a successful challenge would make them unenforceable. Guiding Principle
9 confirms that while ‘[n]o obligation may result for other States from the unilateral

87 ILC, ‘Report of the Commission to the General Assembly on the work of its fifty-eighth session’ (1
May-9 June and 3 July-11 August 2006) UN Doc A/CN.4/SER.A/2006/Add.1 (Part 2), para 176.
88 Ibid para 174.
89 Ibid para 176.
90 Harry S Truman, ‘150 - Proclamation 2667 - Policy of the United States with Respect to the Natural
Resources of the Subsoil and Sea Bed of the Continental Shelf’ September 28, 1945.
91 Convention on the Continental Shelf (adopted 29 April 1958, entered into force 10 June 1964) 499
UNTS 311.
92 ILC, ‘Eighth report on unilateral acts of States, by Mr. Víctor Rodríguez Cedeño, Special Rapporteur’
(26 May 2005) UN Doc A/CN.4/557, paras 131-133.
93 North Sea Continental Shelf (n 6) para 100.
94 UN Doc A/CN.4/557 (n 92) paras 85-88.
95 Ibid para 94.
96 Julia Lisztwan, ‘Stability of maritime boundary agreements’ (2012) 37 Yale Journal of International
Law 153, 165.