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The documents and materials published on this website were collected, researched, and prepared with advice from experts, as a part of a Government-commissioned project. The contents of this website do not reflect the views of the Government. Links to external sites (domains other than https://www.cas.go.jp) are not under the management of this site. For linked websites, please check with the organization/group that manages the website for the link in question.
Expert Columns
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The Ideal Ming Dynasty Coastal Defense and the Senkaku Islands in the Wubei Zhi
Published on October 20, 2025
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What are China’s Aims with the Ten-Dash Line in the South China Sea?
Published on Spetember 9, 2024
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China’s erosion of UNCLOS: Distortion through domestic legislation and interpretation
Published on June 26, 2023
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Mid-Ocean Archipelagos and Law of the Sea
Published on June 26, 2023
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On the Expression of “Effective Control”
Published on Oct 3, 2023
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Function of Maps in Territorial Disputes ― Treatment of Maps by International Tribunals ―
Published on April 22, 2022
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Understanding the Senkaku Islands through the Materials on the Senkaku Islands Archives Portal
Published on April 22, 2022
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The Senkaku Islands, Takeshima and International Adjudication [Addendum] The Northern Territories from the Perspective of International Law
Published on December 18, 2020
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How were the waters and islands of Senkaku used in premodern times?
Published on December 18, 2020
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Where is “Diaoyu Tai,” which China asserts as part of Taiwan, located?
Published on December 18, 2020Commentary Video
Commentary Video
The Story of the Senkaku Islands’ Territorial Incorporation
The Story of the Senkaku Islands’ Territorial Incorporation
Part 1: Okinawa Prefecture’s Investigations of the Senkaku Islands
Commentary Video
The Story of the Senkaku Islands’ Territorial Incorporation
The Story of the Senkaku Islands’ Territorial Incorporation
Part 2: Backgrounds Behind Growing Fisheries Operations and Incorporation into the Prefectural Jurisdiction
Commentary Video
The Story of the Senkaku Islands’ Territorial Incorporation
The Story of the Senkaku Islands’ Territorial Incorporation
Part 3: Groundless Assertions by the People’s Republic of China (PRC)
Commentary Video
The Seas and Islands of Senkaku in the Premodern Era Part1
Commentary Video
The Seas and Islands of Senkaku in the Premodern Era Part2
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- Expert commentaries on the various issues
- Archive of documents and materials
- An archive of documents and materials prepared under the document research project commissioned by the Government of Japan
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