1 Introduction
China’s maritime laws reflect the country’s sense of weakness as a geographically disadvantaged state in Northeast Asia. While China is a large continental power, it lacks strategic depth along its maritime approaches and is unable to reach the high seas without going through the exclusive economic zone (eez) of its neighbors, from Russia to Japan to the Philippines. To address this sense of exposure or vulnerability, China has sought to develop a sense of greater security through excessive or unlawful maritime claims or assertions of entitlement to its maritime approaches or near seas. China has advanced a series of excessive or unlawful maritime claims that seek to place more water under its sovereignty, sovereign rights, and jurisdiction at the expense of its neighbors and even distant coastal States.
These departures from standard state practice and black letter legal doctrine, coupled with China’s bold (sometimes galling) disregard for the lawful maritime boundaries of virtually all of its neighbors, reflects the country’s increasing economic and military power and the confidence they have engendered. This dynamic has also caused clashes with Japan, the United States, and other maritime powers. Japan is affected by Chinese offshore claims because moving Chinese baselines farther east purports to move the equidistant line from which maritime boundary negotiations use as a point of departure. Any effect on Japan has ramifications for American security, which is linked to Japanese stability, prosperity, and security in East Asia. China’s claims also attempt to reduce the operating space of foreign naval forces, such as the U.S. Navy. Likewise, because Japanese security is linked to the United States, any diminution of U.S. and allied operational flexibility or maritime operating space resulting from Chinese excessive claims in the oceans undermines Tokyo’s security, sovereignty, and independence.
2
2.1 Baselines
A state’s maritime zones are measured from baselines. The rules for drawing baselines are contained in articles 5 to 11 and 13 and 14 of unclos. The Law of the Sea Convention distinguishes between normal baselines, which follow the low-water marks along the coast, and straight baselines, subject to specific geographical circumstances. Improperly drawn baselines may significantly extend coastal State jurisdiction seaward in a way that prejudices freedom of navigation and overflight and other internationally lawful uses of the sea. An objective application of the baseline rules contained in unclos restrains extravagant coastal State claims over the global commons and protects the rights and freedoms of all nations.
Normal baselines run along the low-water mark of the coast.1 The United States recognizes normal baselines as the principal method for drawing baselines. In the case of islands situated on atolls or of islands having fringing reefs, the normal baseline is the seaward low-water line on the drying reef chartered as being above the level of chart datum.2 While unclos does not address reef closing lines, any such line may not diminish freedom of navigation and overflight and other internationally lawful uses of the sea.
Straight baselines may be appropriate to enclose waters which, because of their close interrelationship with the land, have the character of internal waters. By using straight baselines, a state may also eliminate complex patterns of geometry or smooth out contiguities in the coastline, such as enclaves, in its territorial sea, that otherwise would result from the use of normal baselines. Straight baselines can eliminate these irregularities or enclaves in the territorial sea that would otherwise result from the use of normal baselines.3 Properly drawn straight baselines do not result in a significant extension of the limits of the territorial sea seaward from those that would result from the application of normal baselines. Furthermore, with the introduction of the eez, the rationale for the use of straight baselines has all but disappeared since they were proposed originally to internalize coastal State fisheries near the coast. By using lawful low water basepoints along the coast to measure the territorial sea and eez, states may address irregularities that appear on the coast without
The use of straight baselines today in a way that prejudices international navigation, overflight, and communications interests of other states is counter to the vision of unclos as a constitution for the world’s oceans and protection of community interests. Consequently, the United States asserts that straight baselines should be used sparingly, and where they are used, they should be drawn conservatively to reflect the one rationale for their use that is consistent with the unclos, namely the simplification and rationalization of the measurement of the territorial sea and other maritime zones off highly irregular coastlines.
Straight baselines in accordance with these rules may be used only in geographic situations where the coastline is deeply indented and cut into or if there is a fringe of islands along the coast in the immediate vicinity of the coast.5 In such cases, states may continue to use normal baselines running along the low-water mark along the coast. The U.S. view is that “deeply indented and cut into” refers to a very distinctive coastal configuration in which a locality is deeply indented and cut into dash there exist at least three indentations that are deep and in close proximity to one another.6 The depth of penetration of each deep indentation from the proposed straight baseline is, as a rule, greater than half the length of that baseline segment. The “fringe of islands along the coast in the immediate vicinity of the coast” refers to several islands.7 The United States asserts that the most landward point of each island should lie no more than 24 miles from the mainland coastline. Each island to which a straight baseline is to be drawn is not more than 24 miles apart from the island from which the
Straight baselines must not depart to any appreciable extent from the general direction of the coast and the sea areas lying within the lines must be sufficiently closely linked to the land domain to be subject to the regime of internal waters.8 The United states has taken the position that to be consistent with this provision, straight baseline segments must not depart to any appreciable extent from the general direction of the coastline, by reference to general direction lines which in each locality shall not exceed 60 miles in length; not exceed 24 miles in length individually; and result in sea areas situated landward of the straight baseline segments that are sufficiently closely linked to the land domain to be subject to the regime of internal waters.9 Minor deviations from these rules do not necessarily mean the straight baselines are inconsistent with the law of the sea.
Straight baselines shall not be drawn to and from low tide elevations, unless lighthouses or “similar installations” which are permanently above sea level have been built on them or except in instances where the drawing of baselines to in from such elevations has received general international recognition.10 “Similar installations” are those that are permanent, substantial, and used for safety of navigation. “General international recognition” includes recognition by the major maritime users over a long period of time. Basepoints for all straight baselines must be located on land territory and situated on or landward of the low water line. No straight baseline segment may be drawn to a base point located on the land territory of another state.11
The United States adheres to the regime of baselines as set forth in unclos. While the United States is not party to unclos, it relies on the Presidential Proclamation of March 10, 1983, which states that the treaty reflects customary international law in respect to the principles that underlie the proper and legal establishment of baselines.12 The normal baseline for measuring the breadth of the territorial sea is the low-water line along the coast.13 Straight baselines are limited to two specific geographic situations: (1) “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.”14 Furthermore, “the sea areas lying within
2.2 China’s Baseline Law
China has widespread use of straight baselines and does not apply them conservatively. In 1958, China claimed for all territories a 12 nm territorial sea measured from straight baselines, including along the mainland and territories of Taiwan and its islands, the Pescadores (Penghu) Islands (an archipelago of 90 islands and islets in the Taiwan Strait), Pratas (Dongsha or Tungsha) Islands (administered by Taiwan), the Paracel (Xisha or Hsisha) Islands, Macclesfield Bank (Chungsha or Qiongzhou), Spratly (Nansha) Islands and “all other islands belonging to China.”16 The claims did not include specific geographic points.
Numerous islands inside the baselines were claimed as “islands of the Chinese inland waters.”17 These include Dongyin (Tungyin) Island, Gaodeng Island (Kaoteng Island), some 36 Matsu Islands, the Paichuan Islands, Wuchiu Island, the Greater and Lesser Quemoy Islands, Tatan Island, Erhtan Island and Tungting Island.18 China also claims the waters in Bohai Bay (Gulf of Pohai) and Chiungchow (Hainan) Strait enclosed in baselines as “inland waters.”19
China has few indentations along the mainland coast, and these are relatively modest and may qualify as historic bays, but not justify the complete straight baseline system along the entire length of the coast of mainland China. In the Fisheries Jurisdiction Case, for example, the Court held that Norway’s coastline typifies an area amenable to straight baselines because the contiguity is “[v]ery broken along its whole length, it constantly opens out into indentations often penetrating for great distances inland: the Porsangerfjord, for instance, penetrates 75 sea miles inland.”20 While parts of China’s coastline are deeply indented and cut into, the indentations are quite modest, while China has pushed straight baselines miles out into the ocean.
On February 25, 1992, The Law of the People’s Republic of China on the Territorial Sea reiterated territorial title claims over mainland of China and
On May 15, 1996, China declared straight baselines along most of its coastline, from which it measures the breadth of its territorial sea, contiguous zone, and its other claimed maritime zones.23 That same day, China claimed an eez and ratified unclos. China announced the baselines of part of its territorial sea adjacent to the mainland and those of the territorial sea adjacent to the Paracel (Xisha) Islands. The baseline system is comprised of 49 base points along the coast running from Shandong Peninsula to the west coast of Hainan Island. The 48 segments that connect the 49 base points total 1,734.1 miles.24 The segments range in length from 0.1 miles (segment 45–46 on Hainan Island) to 121.7 miles (segment 8–9 off the northeast coast of China).25 China notified the United Nations of these geographical coordinates on July 5, 1996. The 1996 Declaration did not address China’s baseline from its land boundary terminus with North Korea, including the Pohai (Bo-Hai) area, or along its coast in the Gulf of Tonkin, or around other islands it claims in the South China Sea. Unlike Vietnam, however, China has not claimed Tonkin Gulf as historic internal waters, despite the straight baseline connecting Hainan Island to the mainland.26
Over half of the baseline segments (25 of the 48 segments) are more than 24 miles in length, with three (6 percent) of the segments exceeding 100 miles.27
China also uses low-tide elevations to connect its straight baseline system in violation of unclos. Low-tide features may be used in accordance so long as they are within 12 nm of the mainland or an island.28 China purports to use at least one low-tide elevation beyond this limit, however.29
The length and location into the sea of many of China’s baseline points indicate that the straight baseline system along the mainland coast is incompatible with unclos, and that China should be using a normal baseline system along its coast. The United States has stated that baseline segments should not exceed 24 miles in length.30 The 24-mile maximum segment length is implied from a close reading of the relevant articles unclos.31
Baselines shall be in the “immediate vicinity” of the coast.32 Furthermore, “the sea areas lying within the line must be sufficiently closely linked to the land domain to be subject to the regime of internal waters.”33 The U.S. views this text as a strong implication that the waters to be internalized would otherwise be part of the territorial sea.34 From this perspective it is “difficult to envision a situation where international waters (beyond 12 miles from the appropriate low-water line) could be “sufficiently closely linked” as to be converted to internal waters.35 A 1989 U.N. study concluded that determination of whether conditions apply that would permit the use of straight baselines requires application of the “spirit as well as the letter of the first paragraph of article 7.”36
Furthermore, even if the baselines were valid, the right of non-suspendable innocent passage still “shall apply” to such areas that previously were open to navigation and later enclosed within straight baselines.37 The continuance of transit rights through the regime of innocent passage preserves pre-existing
China also skirts the rules on fringing islands.40 Although there is a fringe of islands farther south along the Taiwan Strait, most of the basepoints are disconnected from them and they lie at a distance greater than 12 miles from the coast, and at one point some 50 miles.41 China’s basepoints purport to enclose waters that are not “closely linked to the land domain.”
The straight baseline systems along the mainland coast of China also cuts off the eastern approaches to Hainan (Qiongzhou) Strait, a strait used for international navigation. The right of transit passage applies in the strait.42 China might suggest that this straight baseline is lawful because it predates adoption of rules in unclos, but this position is not convincing for the same reason all of China’s historic claims fail – the entire point of the treaty was to ensure states conform to the new metrics.
China also may claim that for ships of all flags except Vietnam or China or Tonkin Gulf destination shipping, Qiongzhou Strait qualifies for the “Messina exception” to transit passage, thereby limiting international shipping to non-suspendable innocent passage because a route of similar convenience already exists to the east and south of Hainan Island.43 For example, a container ship underway from the port of Yokohama bound for Busan via the Strait of Malacca certainly has a route of similar convenience outside of Hainan Strait. This appears to be a reasonable argument for most international shipping that is transiting the South China Sea and not entering Tonkin Gulf. Regardless of whether the navigational regime of non-suspendable innocent passage in the “Messina exception” might apply for most international shipping through Qiongzhou Strait, this exception to transit passage is not dependent on the validity of straight baselines.44
2.2.1 Paracel Islands Straight Baseline Claims
A second system of straight baselines is declared around the Paracel Islands, surrounded by 28 basepoints completely enclosing the islands.46 the law of the sea convention, however, restricts the application of archipelagic straight baselines 2 archipelagic States there are “constituted wholly by one or more archipelagos and may include other islands.”47 An “archipelago” “means a group of islands, including parts of islands, interconnecting waters and other natural features which are so closely inter related that such islands, waters and other natural features form an intrinsic geographic, economic and political entity, or which historically have been regarded as such.”48
The convention also provides, in Article 7, for states to make use of straight baselines under certain circumstances, and the tribunal is aware of the practice of some states in employing straight baselines with respect to offshore archipelagos to approximate the effect of archipelagic baselines. In the tribunal’s view any application of straight baselines to the Spratly islands in this fashion would be contrary to the convention.
Article 7 provides for the application of straight baselines only “in localities where the coastline is deeply indented and cut into or if there is a fringe of islands along the coast in its immediate vicinity.” These conditions do not include the situation of an offshore archipelago. Although the convention does not expressly preclude the use of straight baselines in other circumstances, the tribunal considers that the grant of permission in Article 7 concerning straight baselines generally, together with the conditional permission in Articles 46 and 47 for certain states to draw archipelagic baselines, excludes the possibility of employing straight baselines in other circumstances, in particular with respect to offshore archipelagos not meeting the criteria for archipelagic baselines. Any other interpretation would effectively render the conditions in articles 7 and 47 meaningless. Notwithstanding the practice of some states to the contrary, the tribunal sees no evidence that any deviations from this rule have amounted to the formation of a new rule of customary international law that would permit a departure from the express provisions of the convention.50
[T]to the extent China’s claim to “internal waters” contemplates waters within straight baselines around any South China Sea Island, the United States objects … Consistent with international law as reflected in the Law of the Sea Convention, including Articles 5, 7, 46, and 47, China cannot claim straight or archipelagic baselines in the Paracel Islands, Pratas Island, Maccelesfield Bank, Scarborough Reef, or the Spratly Islands. Similarly, China’s claims related to what it calls “Nanhai Zhudao (the South China Sea Islands),” and to “Dongsha Qundao (the Dongsha Islands), Xisha Qundao (the Xisha Islands), Zhongsha Qundao (the Zhongsha Islands) and Nansha Qundao (the Nansha Islands)” would be unlawful to the extent they are intended to include any maritime claim based on grouping multiple islands together as a single unit for purposes
of establishing internal waters, territorial sea, contiguous zone, exclusive economic zone and continental shelf or any other maritime claim.51
2.2.2 Senkaku Islands Straight Baseline Claims
The 1996 declaration published geographical coordinates for straight baselines for most of the Chinese coastline, and the Paracel (Xisha) Islands. China claimed straight baselines around the Senkaku Islands in a statement on September 10, 2012.52 Aside from the overlapping claims of sovereignty by Japan and China, the United States objected based on excessive straight baseline claims. The U.S. does not recognize these claims and protested them in 1996 and 2013 and conducted operational assertions in fiscal years 1997, 2011, 2013 through 2016.53
The Government of the United States notes that the Statement lists 17 base points that connect to create two straight baseline systems around two groups of islands known collectively in the United States as the Senkaku Islands (China refers to the islands as the Daioyu Islands). The first system of straight baselines consists of 12 segments enclosing Uotsuri Shima (Diaoyu Dao), Kuba Shima (Huangwei Yu), Minami Kojima (Nanxiao Dao), and certain other features. The second system of straight baselines consists of 5 segments surrounding one island, Taisho To (Chiwei Yu) and its surrounding features. The United States recalls that, as recognized in customary international law and as reflected in Part ii of the [unclos], except where otherwise provided in the 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. As provided for in Article 7 of the Convention, only in localities where the coastline is deeply indented and cut into, or if there is a fringe of islands along the coast in its immediate vicinity, may the coastal State elect to use the method of straight baselines joining appropriate points in drawing the baseline from which the breadth of the territorial sea is measured.
The Senkaku Islands comprise several small features spread over an area of approximately 46 square nautical miles. The United States takes no position on the ultimate sovereignty of the Senkaku Islands. Irrespective of sovereignty claims, international law does not permit the drawing of straight baselines around these features. The Senkaku Islands do not meet the specific geographic requirements for the drawing of straight baselines because their coastline is not deeply indented and cut into, and they do not constitute a fringe of islands along the coast in its immediate vicinity.
To the extent that the Statement might be intended to suggest that archipelagic baselines may be drawn around the Senkaku Islands, this also would be inconsistent with international law. Under customary international law, as reflected in Part iv of the Law of the Sea Convention, only “archipelagic States” may draw archipelagic baselines joining the outermost points of an archipelago. Coastal States, such as China and the United States, do not meet the definition of an “archipelagic State” reflected in Part iv of the Convention. China, therefore, may not draw
archipelagic baselines enclosing offshore islands and waters, and the proper baseline for such features is the low-water line of the islands. … These baselines, as asserted, impinge on the rights, freedoms, and uses of the sea by all nations by expanding the seaward limit of maritime zones and enclosing as internal waters areas that were previously territorial sea.
The United States requests that the Government of China review its current practice on baselines, explain its justification under international law when defining its maritime claims, and make appropriate modifications to bring these claims into accordance with international law as reflected in [unclos]….55
2.2.3 China’s Historic Internal Waters Claims
Internal waters are those landward of the baseline.56 Article 2 makes clear the generally recognized rule that coastal State sovereignty extends to internal waters. In articles 218 and 220, the Convention adds to general notions of sovereignty and jurisdiction over internal water by expressly authorizing port state enforcement action within internal waters for pollution violations that have occurred elsewhere. This authorization does not imply any limitation on other enforcement actions that coastal States may choose to exercise in their ports or other internal waters.
When the establishment of a straight baseline … has the effect of enclosing as internal waters areas which had not previously been considered as such, a right of innocent passage as provided in this convention shall exist in those waters.
If a foreign flag vessel is found in a coastal State’s internal waters without its permission, the full range of reasonable enforcement procedures is available
China’s dashed line claim in the South China Sea is an attempt at a claim of historic internal waters. Yet, there is no coherent legal basis for its “Nine-Dashed Line” claim in the South China Sea, which was formally announced in a note verbale in 2009. As Secretary of State Michael Pompeo stated, “China uses intimidation to undermine the sovereign rights of Southeast Asian coastal States in the South China Sea, bully them out of offshore resources, assert unilateral dominion, and replace international law with “might makes right.”58 Beijing’s approach has been clear for years. In 2010, then-prc Foreign Minister Yang Jiechi told his asean counterparts that “China is a big country and other countries are small countries and that is just a fact.”
An Annex vii Arbitral Tribunal constituted under unclos held unanimously on July 12, 2016, that China’s maritime claims have no basis in international law and do not perfect valid historic internal waters claims. On July 13, 2020, the United States aligned itself with the Tribunal’s decision.
Claims to historic waters should comport with the three-part test in international law as restated by the United Nations in 1962: (1) exercise of authority over the waters; (2) continuity of the exercise of authority; and (3) acquiescence or acceptance by neighboring states.59 China’s “nine-dash line” claim does not pass this three-part test. Furthermore, sovereignty over land features may be claimed under international law only in five circumstances: (1) accretion, that is a build-up through natural geologic processes, such as a volcanic eruption, (2) cession, or voluntary transfer via treaty, (3) conquest, but only before adoption of the UN Charter in 1945, (4) occupation of terra nullius, that is not mere inchoate discovery, but actual occupation, and (5) prescriptive exercise of authority that is public, peaceful and extending over a long period of time. The burden of proof is on the claimant state to present facts and law in support of the claim.
United Nations Convention on the Law of the Sea art. 5, Dec. 10, 1982, 1833 U.N.T.S. 397 [hereinafter unclos].
unclos, art. 6.
United Nations, Baselines: An Examination of the Relevant Provisions of the United Nations Convention on the Law of the Sea 17 (1989).
Anglo-Norwegian Fisheries Case (U.K. v. Nor.), Judgment, 1951 i.c.j. Rep. 116, 128, 142–43 (Dec. 18).
unclos, art. 7.
United Nations Convention on the Law of the Sea, Message from the President of the United States Transmitting, Sen. Treaty Doc. 103–39, p. 9 (Sen. Treaty Doc. 103–39).
unclos, art. 121.
unclos, art. 7(3).
Sen. Treaty Doc. 103–39, p. 9.
unclos, art. 7(4).
Sen. Treaty Doc. 103–39, p. 10.
unclos, arts. 5–11 and 13–14.
unclos, art. 5.
unclos, art. 7.
unclos, art. 7(3).
Declaration on the Territorial Sea (September 4, 1958), ¶ 4, reprinted in Department of State, Limits in the Seas No. 43, Straight Baselines: People’s Republic of China 2–6 (July 1, 1972, July 31, 1978).
Id., ¶ 2.
Id., ¶ 2.
Declaration on the Territorial Sea (September 4, 1958), ¶ 3.
Id., 133.
Law on the Territorial Sea and the Contiguous Zone of 25 February 1992, reprinted in Annex 2, Department of State, Limits in the Seas No. 117, Straight Baseline Claims: China (July 9, 1996).
Law on the Territorial Sea and the Contiguous Zone of 25 February 1992, art. 2.
Declaration of the Government of the People’s Republic of China on the baselines of the territorial sea, 15 May 1996.
Department of State, Limits in the Sea No. 117, at 4.
Limits in the Sea No. 117, at 4.
Department of State, Limits in the Seas No. 99, Straight Baselines: Vietnam 9–10 (1983). In 2000, China and Vietnam entered into a maritime boundary agreement in the Gulf of Tonkin that entered into force June 30, 2004. Report No. 5–25, at 3745–3758 (2005).
Limits in the Sea No. 117, at 4.
unclos, art. 13.
Limits in the Sea No. 117, at 6 (dma chart 94260, point 10).
U.S. Department of State Dispatch Supplement, Law of the Sea Convention, Letters of Transmittal and Submittal and Commentary, Vol. 6, February 1995, p. 8. See also, Victor Prescott, The Maritime Political Boundaries of the World 69 (1985).
Limits in the Sea No. 117, at 5.
unclos, art. 7(1).
unclos, art. 7(3).
Limits in the Sea No. 117, at 5.
Id.
United Nations, Baselines: An Examination of the Relevant Provisions of the United Nations Convention on the Law of the Sea, 1989, p. 17.
unclos, art. 8(2).
Limits in the Sea No. 117, at 5.
Department of State, Limits in the Sea No. 106, Developing Standard Guidelines for Evaluating Straight Baselines 14 (August 31, 1987).
unclos, art. 7(1).
Limits in the Sea No. 117, at 7.
unclos, art. 37.
unclos, art. 38(1).
James Kraska, “China and Canada are Unlikely to Collaborate on Unlawful Straight Baselines,” 19 Chinese Journal of International Law 803, 804 (2020).
Zou Keyuan, China’s Marine Legal System and the Law of the Sea 92–94 (2005).
Limits in the Seas 117 at 8 (citing China’s 1992 and 1996 laws).
unclos, art. 46.
Id.
Vietnam, Dispute Regarding the law on the exclusive economic zone in the continental shelf of the People’s Republic of China, which was passed on 26 June 1998, communicated by the Permanent Mission of the Socialist Republic of Viet Nam to the United Nations in a note verbale dated 6 August, 1998, reprinted in 38 Law of the Sea Bulletin 54–55 (1998).
South China Sea Arbitration (Phil. v. China), Case No. 2013-19, Award, ¶ 575–576 (Perm. Ct. Arb. 2016).
United States Note Verbale to People’s Republic of China, December 28, 2106, available at
China, “Statement of the Government of the People’s Republic of China on the Baselines of the Territorial Sea of Diaoyu Dao and Its Affiliated Islands,” 10 September 2012, reprinted in 80 Law of the Sea Bulletin 30–31 (2012).
Department of Defense Representative for Ocean Policy Affairs (repopa), Maritime Claims Reference Manual (mcrm) (January 2017). (Issued pursuant to DoD Instruction S-2005.01, Freedom of Navigation (fon) Program (U), October 20, 2014).
Digest of United States Practice in International Law 369–370 (CarrieLyn D. Guymon, ed. 2013).
China’s claimed baselines of the territorial sea of the Senkaku Islands, Digest of United States Practice in International Law Ch. 12, 369–370 (2009–2013).
unclos, art. 8(1).
Id., arts. 25 and 30.
Michael R. Pompeo, U.S. Secretary of State, U.S. Position on Maritime Claims in the South China Sea, July 13, 2020.
UN Doc. A/cn.4/143, “Juridical Regime of Historic Waters Including Historic Bays – Study prepared by the Secretariat,” 2 Yearbook of the International Law Commission 1–27 (1962).
Ken Booth, Law, Force, and Diplomacy at Sea 164 (1985).