Nine-dash line — LLMpedia

Nine-dash line
Name	Nine-dash line
Location	South China Sea

Contents

Nine-dash line

The nine-dash line is a maritime demarcation used in certain maps to indicate claimed waters in the South China Sea by authorities in People's Republic of China and predecessors in Republic of China (1912–1949). It overlaps with maritime zones claimed by Vietnam, Philippines, Malaysia, Brunei, and Indonesia and has been central to disputes involving Permanent Court of Arbitration (The Hague), United Nations Convention on the Law of the Sea, and naval interactions between United States Navy, People's Liberation Army Navy, and regional coast guards.

Background and origins

The line traces antecedents to maps produced by the Republic of China (1912–1949) and cartographers during the Republic of China era, with echoes in maps published in the period of Chiang Kai-shek and Kuomintang administrations, and intersects with historic references to the Spratly Islands, Paracel Islands, Pratas Islands, Scarborough Shoal, and historic voyages of Zheng He. Early cartographic predecessors appeared in publications associated with Ministry of Foreign Affairs (Republic of China), colonial charts by British Admiralty, and Japanese maps from the era of Empire of Japan occupation. The demarcation has been rationalized with appeals to historical maps, records from Ming dynasty and Qing dynasty, and references to maritime activities involving South China Sea trade routes, Maritime Silk Road, and fishing by communities in Hainan and Fujian.

The line’s legal status is contested in relation to UNCLOS and rulings by the Permanent Court of Arbitration (The Hague), notably the 2016 arbitration initiated by Philippines under Benigno Aquino III against claims asserted by People's Republic of China. The tribunal considered claims involving exclusive economic zone entitlements for features such as Second Thomas Shoal and Reed Bank, and addressed issues under provisions involving Articles of UNCLOS and principles codified in International Tribunal for the Law of the Sea jurisprudence. Responses to the tribunal involve positions taken by United States Department of State, European Union External Action Service, and governments of Japan, Australia, and India, with debates invoking precedent from disputes like Nicaragua v. Honduras and institutional frameworks such as the Association of Southeast Asian Nations and its Declaration on the Conduct of Parties in the South China Sea.

Maps produced by agencies including the State Oceanic Administration (China), National Mapping Agency (Taiwan), and historical cartographers show multiple-digitized dash counts, varying from eleven-dash maps used during the Republic of China (1912–1949) period to nine-dash and ten-dash variants appearing in modern atlases and publications by China National Geographic, Xinhua, and foreign publishers such as Rand McNally and National Geographic. Differences appear on charts from the British Admiralty, United States Geological Survey, and Hydrographic Office (Royal Navy), and in mapping controversies involving digital platforms run by Google Maps, Baidu Maps, and TomTom.

Positions differ: People's Republic of China and Republic of China (Taiwan) maintain claims tied to historical assertions, while Philippines, Vietnam, Malaysia, Brunei, and Indonesia assert maritime entitlements under UNCLOS and base claims on proximity to features like Spratly Islands and Paracel Islands. External actors such as United States, Japan, Australia, United Kingdom, and European Union have articulated positions through diplomatic statements, freedom of navigation operations by the United States Seventh Fleet, and policy papers from ministries like Ministry of Foreign Affairs (Japan) and Department of Foreign Affairs (Philippines).

Tensions have produced standoffs including confrontations around Scarborough Shoal between Philippines and People's Republic of China vessels, the 2012 Scarborough Shoal standoff, collisions involving research ships like Vietnam Fisheries Surveillance, blockade incidents at Second Thomas Shoal, and freedom of navigation encounters between USS Decatur (DDG-73) and Chinese ships. Incidents have involved coast guards such as China Coast Guard, Philippine Coast Guard, and Royal Malaysian Navy, and raised involvement from legal entities like International Criminal Court only indirectly via political debate, with crises prompting diplomatic notes exchanged among Ministry of Foreign Affairs (People's Republic of China), Department of Foreign Affairs (Philippines), and ASEAN foreign ministers.

Claims delineated by the line affect access to fisheries around Scarborough Shoal, hydrocarbon prospects at sites like Reed Bank and Spratly Islands basins, and shipping lanes used by vessels from ports such as Singapore, Hong Kong, and Kaohsiung. Energy companies including ExxonMobil, PetroVietnam, CNOOC, and Rosneft have been implicated in exploration disputes, while markets for goods transiting through the Strait of Malacca and the Luzon Strait adjust to geopolitical risk assessed by firms like Lloyd's of London and analysts at IHS Markit and International Energy Agency.

Efforts include bilateral negotiations between China–Philippines relations, multilateral diplomacy within ASEAN, confidence-building measures referenced in the Declaration on the Conduct of Parties in the South China Sea, and the ongoing pursuit of a Code of Conduct in the South China Sea negotiated by People's Republic of China and Association of Southeast Asian Nations. Third-party involvement and arbitration like the 2016 Permanent Court of Arbitration (The Hague) case, as well as track-two dialogues facilitated by institutions such as Sciences Po, International Crisis Group, and Asia-Pacific Center for Security Studies, continue to shape prospects for dispute management.

Category:South China Sea disputes