China’s Straight Baseline Claim: Senkaku (Diaoyu) Islands

Introduction

On September 10, 2012, the People’s Republic of China issued a Government Statement setting forth the coordinates of straight baselines in the East China Sea (see Annex 1).[1] China’s newly published baseline coordinates enclose two groups of maritime features that are claimed by China, Japan, and Taiwan. They are known variously as the Senkaku (by Japan), Diaoyu (by China), Tiaoyutai (by Taiwan), or Pinnacle (by the United Kingdom) Islands.[2] On September 21, 2012, China deposited with the United Nations a list of these coordinates and an illustrative chart.[3] On September 24, 2012, Japan protested the Chinese straight baseline claim.[4]

Japan formally claimed the islands in 1895, and, with the exception of the 1945-1972 U.S. civil administration of the area after World War II, Japan continues to administer these islands with de facto U.S. recognition.[5] Japan did not draw straight baselines around these features when it promulgated its Territorial Sea Law in 1996.[6]

China’s September statement said that the baselines were “in accordance with the ‘Law of the People’s Republic of China on Territorial Sea and Its Contiguous Zone’ of 25 February 1992.”  Article 2 of that law claims Diaoyu Island (and associated islands) as part of China’s land territory.  Article 3 of the same law provides that “the method of straight baselines composed of all the straight lines joining the adjacent basepoints shall be employed in drawing the baselines of the territorial sea of the People’s Republic of China.”[7] Four days later, China stated that these baselines were “consistent with relevant provisions of the UN Convention on the Law of the Sea (“UNCLOS”).”[8]

This Insight analyzes the Senkaku (Diaoyu) claims and the use of straight baselines,[9] an exception to the normal rules for determination of baselines (see below).[10]

Basis for Analysis of the Baseline Claim[11]

China is a party to the 1982 Law of the Sea (“LOS”) Convention, which provides in Article 5, “except where otherwise provided in this Convention, the normal baseline for measuring the breadth of the territorial sea is the low-water line along the coast as marked on large-scale charts officially recognized by the coastal State.”  China’s 1992 law makes no mention of the normal baseline.

Straight baselines are never mandatory, but may be elected by a State under Articles 7 and 46 of the LOS Convention.  Article 7 provides for two distinct geographical situations where a State may employ straight baselines in drawing the baseline from which the breadth of the territorial sea[12] is measured: (1) “in localities where the coastline is deeply indented and cut into,” and (2) “if there is a fringe of islands along the coast in its immediate vicinity.”

The LOS Convention, Article 46, also permits an archipelagic State[13] to draw “straight archipelagic baselines joining the outermost points of the outermost islands and drying reefs of the archipelago,” provided certain criteria are met.  The use of archipelagic straight baselines by archipelagic States is not mandated by the LOS Convention, but if used must be so claimed with due publicity (Article 47(9)).

Straight Baselines

The purpose of authorizing the use of straight baselines is to allow the coastal State, at its discretion, to enclose those waters which, as a result of their close interrelationship with the land, have the character of internal waters.  By using straight baselines, a State may also eliminate complex patterns, including enclaves, in its territorial sea, that would otherwise result from the use of normal baselines.[14] Properly drawn straight baselines do not result in extending the limits of the territorial sea significantly seaward from those that would result from the use of normal baselines.[15]

The International Court of Justice has made it clear that

the method of straight baselines, which is an exception to the normal rules for the determination of baselines, may only be applied if a number of conditions are met.  This method must be applied restrictively.  Such conditions are primarily that either the coastline is deeply indented and cut into, or that there is a fringe of islands along the coast in its immediate vicinity.[16]

If the portion of the coast being examined does not meet either criterion, then no straight baseline segment may lawfully be drawn in that locality, and the associated rules (on permissible basepoints, the vector of the putative straight baseline in relation to the coast, and the requisite quality of the waters that would be enclosed) may not be invoked.[17] Further, the coastal State must fulfill all the requirements of either test and may not mix the requirements.  For example, a State may not claim that, because a locality is indented, though not deeply, and that it has some islands, though they do not constitute a fringe, it may draw straight baselines there.  Either test selected must be met entirely on its own terms.  If a coastal State cannot establish that its coastline in the locality in which the straight baseline is sought is deeply indented and cut into or fringed with islands in the immediate vicinity, it may not proceed to identify appropriate straight baselines, for none are authorized to be drawn there.  Rather, it must use as a baseline in that locality its low-water mark.  Failure to meet this preliminary geographical test in one locality does not preclude establishing it in another. 

“Localities Where the Coastline Is Deeply Indented and Cut into”

“Deeply indented and cut into” refers to a very distinctive coastal configuration.  The United States has taken the position that such a configuration must fulfill all of the following characteristics:[18]
 

• in a locality where the coastline is deeply indented and cut into, there exist at least three deep indentations;
• the deep indentations are in close proximity to one another; and
•  the depth of penetration of each deep indentation from the proposed straight baseline enclosing the indentation at its entrance to the sea is, as a rule, greater than half the length of that baseline segment.[19]

The term “coastline” is the mean low-water line along the coast; the term “localities” refers to particular segments of the coastline.[20]

“Fringe of Islands along the Coast in Its Immediate Vicinity”

“Fringe of islands along the coast in its immediate vicinity” refers to a number of islands and not to features that do not meet the definition of an island contained in Article 121(1) of the LOS Convention.[21] The United States has taken the position that such a fringe of islands must meet all of the following requirements:[22]
 

• the most landward point of each island lies no more than twenty-four miles from the mainland coastline;
• each island to which a straight baseline is to be drawn is not more than twenty-four miles apart from the island from which the straight baseline is drawn; and
• the islands, as a whole, mask at least 50% of the mainland coastline in any given locality.[23]

The Senkaku (Diaoyu) Islands do not meet either criterion, according to these requirements.  Hence, the straight baselines described below are inconsistent with the LOS Convention.

Archipelagic States

The LOS Convention, Article 46, describes an archipelagic State as one “constituted wholly by one or more archipelagos” and may include other islands.  It defines an “archipelago” as “a group of islands, including parts of islands, inter-connecting waters and other natural features which are so closely interrelated that such islands, waters and other natural features form an intrinsic geographical, economic and political entity, or which historically have been regarded as such.”

China has correctly not claimed status as an archipelagic State, since an archipelago must consist wholly of islands.  As a continental State that claims offshore groups of islands, China may not claim archipelagic waters.[24]

Criteria for archipelagic baselines are specified in the LOS Convention, Article 47.  For example, the length of the baselines may not exceed 100 miles, except that up to three percent of the total number of baselines may be drawn to a maximum length of 125 miles.  The baselines must be drawn such that the ratio of water to land area enclosed by the baselines is between 1:1 and 9:1.[25] The Chinese straight baselines enclosing the two groups of the Senkaku (Diaoyu) Islands do not meet the water:land ratio.[26] Thus, these baselines could not satisfy the criteria for archipelagic straight baselines even if the group pertained to an archipelagic State.

Geographic Characteristics

The Chinese statement claims straight baselines around two separate groups of uninhabited features: those associated with the Uotsuri Shima (Diaoyu Dao) and with Taisho To (Chiwei Yu).  These two groups are about forty-seven miles apart.  Taken together they are located in the East China Sea, about 177 miles east of China’s mainland, ninety-three miles northeast of Taiwan’s northern coast, and 118 miles west of Kume Jima, Japan (see Map 1).  While the 200-mile EEZ/continental shelf claims of China and Japan overlap in this area, there is no agreed maritime boundary between them.[27] None of the baseline segments exceeds twenty-four miles in length.

The features associated with Uotsuri Shima (Diaoyu Dao) are: Hokusei Kojima (Haitun Dao), Kita Kojima (Xaihuya Dao), Hokuto Kojima (Haixing Dao), Kuba Shima (Huangwei Yu), Haigui Dao (no Japanese name), Changlong Dao (no Japanese name), Minami Kojima (Nanxiao Dao), and Changyu Dao (no Japanese name). Their characteristics are as set out in Tables 1 and 2, reproduced below.

The features associated with Taisho To (Chiwei Yu) are: Wangchi Dao (no Japanese name), Xiaochiwei Dao (no Japanese name), Kita Kojima (Chibeibei Dao), and Chibeidong Dao (no Japanese name).  This small group lies about forty-seven miles to the northeast of the main group described above. The characteristics of these features are as set out in Tables 3 and 4, reproduced below.

There are three other small features enclosed within the straight baselines of the Uotsuri (Diaoyu Dao) group:  Tobise (Fei Yu/Fei Jiao Yan), Okino Minami Iwa (Nan Yu/Da Nan Xiao Dao), and Okinokita Iwa (Bei Yu/Da Bei Xiao Dao).[28]

Maritime Zones of Islands and Rocks

Article 121, the sole separate article in the LOS Convention on islands that constitutes Part VIII on the regime of islands, reads:

1. An island is a naturally formed area of land, surrounded by water, which is above water at high tide.
2. Except as provided for in paragraph 3, the territorial sea, the contiguous zone, the exclusive economic zone and the continental shelf of an island are determined in accordance with the provisions of this Convention applicable to other land territory.
3. Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf.

International courts have not agreed as to which features meet the criteria of paragraph three.[29] With the exception perhaps of Uotsuri Shima (Diaoyu Dao),[30] the largest feature in the two groups, all other features seem to be uninhabitable, unable to sustain human habitation or to have an economic life of their own, and thus would not be entitled to more than a twelve-mile territorial sea.

Neither China nor Japan have explicitly claimed an EEZ or continental shelf from the Senkaku (Diaoyu) Islands, perhaps because they lie within 200 miles of the nearest Chinese and Japanese coastlines, that is, within their overlapping EEZ/continental shelf claims.[31] Accordingly, concerns about potential oil and gas deposits and fishing would be relevant to these features only within the twelve-mile territorial sea generated from them.[32]

About the Author:

J. Ashley Roach, an ASIL member, Captain, JAGC, USN (retired), Office of the Legal Adviser, U.S. Department of State (retired), was recently appointed chair of the International Law Association’s straight baseline committee.  The views expressed in this Insight are not intended to reflect the position of any department of the U.S. Government, except where quoting from or referencing official government positions.  The author gratefully acknowledges the technical assistance of Ray Milefsky and Brian Melchior.

Table 1

Table 2

Table 3

Table 4

Map 1

Annex 1

Statement of the Government of The People’s Republic of China on the Territorial Sea Baselines for Diaoyu Dao and Its Affiliated Islands 10 September 2012 [33]

In accordance with the Law of the People’s Republic of China on Territorial Sea and Its Contiguous Zone of 25 February 1992, the Government of the People’s Republic of China hereby announces the baselines of the territorial sea adjacent to Diaoyu Dao and its affiliated islands of the People’s Republic of China.

I.  The baselines of the territorial sea for Diaoyu Dao, Huangwei Yu, Nanxiao Dao, Beixiao Dao, Nan Yu, Bei Yu, and Fei Yu are composed of all the straight lines joining the adjacent base points listed below:

1.  Diaoyu Dao 1        25°44.1’N, 123°27.5’E
2.  Diaoyu Dao 2        25°44.2’N, 123°27.4’E
3.  Diaoyu Dao 3        25°44.4’N, 123°27.4’E
4.  Diaoyu Dao 4        25°44.7’N, 123°27.5’E
5.  Haitun Dao            25°55.8’N, 123°40.7’E
6.  Xiahuya Dao          25°55.8’N, 123°41.1’E
7.  Haixing Dao           25°55.6’N, 123°41.3’E
8.  Huangwei Yu          25°55.4’N, 123°41.4’E
9.  Haigui Dao             25°55.3’N, 123°41.4’E
10. Hanglong Dao       25°43.2’N, 123°33.4’E
11. Nanxiao Dao         25°43.2’N, 123°33.2’E
12. Changyu Dao        25°44.0’N, 123°27.6’E
1.  Diaoyu Dao 1        25°44.1’N, 123°27.5’E

II. The baselines of the territorial sea adjacent to Chiwei Yu are composed of all the straight lines joining the adjacent base points listed below:

1.  Chiwei Yu             25°55.3’N, 124°33.7’E
2.  Wangchi Dao          25°55.2’N, 124°33.2’E
3.  Xiaochiwei Dao     25°55.3’N, 124°33.3’E
4.  Chibeibei Dao        25°55.5’N, 124°33.5’E
5.  Chibeidong Dao -   25°55.5’N, 124°33.7’E
1.  Chiwei Yu             25°55.3’N, 124°33.7’E

Endnotes: