The nine-dotted line, U-shape line, or nine-dash map (Chinese: 南海九段线; pinyin: nánhǎi jiǔduàn xiàn; literally "Nine division lines of the South China Sea"; Vietnamese: Đường lưỡi bò; literally: "ox's tongue line") refers to the demarcation line used by both the governments of the People's Republic of China and the Republic of China (Taiwan) for their claim in the South China Sea, an area including the Paracel Islands (occupied by China but claimed by Vietnam) and Spratly Islands disputed by the Philippines, China, Brunei, Malaysia, Taiwan, and Vietnam, who each either claim all or part of the Spratlys, which are believed to sit on vast mineral resources, including oil. According to Chinese sources the line first appeared in February 1948 as an eleven-dotted U-shape line in a map appearing in a private publication in the Republic of China.
The Nine-dotted line was originally an "eleven-dotted-line" first indicated by the then Kuomintang government of the Republic of China in 1947 for its claims to the South China Sea. After the Communist Party of China took over mainland China and formed the People's Republic of China in 1949, the line was adopted and revised to nine as endorsed by Zhou Enlai. After evacuating to Taiwan, the Republic of China has continued its claims, and the nine-dotted line remains as the rationale for Taiwan's claims to the Spratly and Paracel Islands.
The dotted line has been used by China as the maximum extent of its claim. However, the dotted lines do not show how the lines would be joined if it was continuous and the extent of area claimed by China. The 9-dotted-line has been officially protested by the Philippines, Vietnam, Malaysia, Brunei and Indonesia. Immediately after China submitted to the UN a map including the 9-dotted lines territorial claim in the South China Sea on May 7, 2009, the Philippines lodged a diplomatic protest against China for claiming the whole of South China Sea illegally. Vietnam and Malaysia filed their joint protest a day after China submitted its 9-dash line map to the UN. Indonesia also registered its protest, even though it did not have a claim on the South China Sea.
Ongoing disputes 
According to Philippine President Benigno Aquino III, "China’s 9-dash line territorial claim over the entire South China Sea is against international laws, particularly the United National Convention of the Laws of the Sea (UNCLOS)". Vietnam also rejected the 9-dotted line claim, citing that it is baseless and against the UNCLOS. In 2010, at a regional conference in Hanoi, Secretary of State Hillary Clinton announced that "The United States has a national interest in freedom of navigation, open access to Asia's maritime commons, and respect for international law in the South China Sea". The United States has also called for unfettered access to the area that China claims as its own, and accused Beijing of adopting an increasingly aggressive stance on the high seas.
While China has never used the 9-dotted line as an inviolable border to its sovereignty, this strategy together with the fact that China's authority has never officially explained the meaning of the 9-dotted line have led many researchers to try to derive the exact meanings of the 9-dotted line map in the Chinese strategy in the South China Sea. Some scholars believe that this line cannot be considered as a maritime boundary line because it violates international law which states that a national boundary line must be a stable and defined one. The 9-dotted line is not stable because it has been reduced from 11 to 9 dashes in the Gulf of Tonkin as endorsed by Zhou Enlai without any reasons given. It is also not a defined line because it does not have any specific geographic coordinates and does not tell how it can be connected if it was a continuous line. In October 2008, the website WikiLeaks published a cable from the U.S. Embassy in Beijing reporting that Yin Wenqiang, a senior Chinese government maritime law expert, had "admitted" he was unaware of the historical basis for the nine dashes.
According to the Kyodo News, in March 2010 PRC officials told US officials that they consider the South China Sea a "core interest" on par with Taiwan, Tibet and Xinjiang, but subsequently backed away from that assertion In July 2010 the Communist Party-controlled Global Times stated that "China will never waive its right to protect its core interest with military means" and a Ministry of Defense spokesman said that "China has indisputable sovereignty of the South Sea and China has sufficient historical and legal backing" to underpin its claims.
At the Conference on Maritime Study organized by the US-based Center for Strategic and International Study (CSIS) in June 2011, Dr. Su Hao from the China Foreign Affairs University in Beijing delivered a speech on China’s sovereignty and policy in the South China Sea using history as the main argument. However, Dr. Termsak Chalermpalanupap, Assistant Director for Program Coordination and External Relations of the ASEAN Secretariat, said: “I don’t think that the 1982 United Nations Convention on the Law of the Sea (UNCLOS) recognizes history as the basis to make sovereignty claims.” This view that history is not the basis for soverignty claim over waters is agreed by Prof. Peter Dutton from the US Naval War College who commented that, “[T]he jurisdiction over waters does not have connection to history. It must observe the UNCLOS.” He did not agree with the explanation of China of the meaning of the 9-dotted line related to history. Dr. Dutton further stressed that using history to explain sovereignty erodes the rules of the UNCLOS. It is understood that China ratified the UNCLOS in 1996.
Maritime researcher Carlyle Thayer, Emeritus Professor of Politics of the University of New South Wales, said that Chinese scholars using historical heritage to explain its claim of sovereignty shows the lack of legal foundation under the international law for the claim. Caitlyn Antrim, Executive Director, Rule of Law Committee for the Oceans of the USA, commented that "The U-shaped line has no ground under the international law because [the] historical basis is very weak". She added "I don’t understand what China claims for in that U-shaped line. If they claim sovereignty over islands inside that line, the question is whether they are able to prove their sovereignty over these islands. If China claimed sovereignty over these islands 500 years ago and then they did not perform their sovereignty, their claim of sovereignty becomes very weak. For uninhabited islands, they can only claim territorial seas, not exclusive economic zones (EEZ) from the islands”.
See also 
- Jamandre, Tessa (14 April 2011). "PH protests China's '9-dash line' Spratlys claim". Malaya. Retrieved 2 June 2011.
- Lam Dien (3 Sep 2009). "An "unacceptable 9-dotted line"". Tuoi Tre Newspaper (Vietnam).
- Peter J Brown (8 Dec 2009). "Calculated ambiguity in the South China Sea". Asia Times Online.
- Jerry E. Esplanada (15 April 2011). "PH runs to UN to protest China’s ‘9-dash line’ Spratlys claim".
- Regina Bengco (2 June 2011). "Aquino mulls UN protest on Spratlys". Maritime Security Asia.
- Hoang Viet (19 May 2009). "Is the "Is the Ox's tongue line legal?"". BBC.
- Associate Press (AFP) (25 July 2010). "Beijing hits out at US comments on South China Sea".
- Foreign Press Center of Vietnam (25 July 2010). "The "9-dashed line" – an irrational claim".
- David Lague (May 24, 2012). "Analysis: China's nine-dashed line in South China Sea". Chicago Tribune.
- Clinton Signals US Role in China Territorial Disputes After Asean Talks, Bloomberg, 2010-07-23.
- American shadow over South China Sea, Global Times, 2010-07-26.
- China Says Its South Sea Claims Are ‘Indisputable’, Bloomberg, 2010-07-29.
- "International scholars discuss maritime security in the East Sea". 22 June 2011.
- "Declarations or Statements upon UNCLOS Ratification". Division for Ocean Affairs and the Law of the Sea, United Nations Office of Legal Affairs. Retrieved February 22, 2013.
- Thayer, Carlyle A. (July 14th, 2011). "South China Sea disputes: ASEAN and China". Retrieved February 22, 2013.
Further reading 
- Beijing Exhibiting New Assertiveness in South China Sea, May 31, 2012 with Nine Dashes map