Lecture at the 2026 Session of the Philippine International Law of the Sea Academy (PHILSEA)

Atsuko Kanehara, Research Director delivered her lecture online on “Territorial Sea, Contiguous Zone, and Innocent Passage,” for The 2026 Session of the Philippine International Law of the Sea Academy (PHILSEA).

The lecture examines the territorial sea regime, as one of the dual sea zones of the law of the sea, along with the high sea regime, starting with its historical development from the 17th century to the 1982 United Nations Convention and the Law of the Sea. Then, her lecture focused upon the innocent passage of foreign vessels. In considering the similar tense situation that the Philippines and Japan have been facing in their sea areas, the lecture provided the following two case studies: first, the way to combat harmful acts by foreign public vessels in territorial sea under the restriction by the immunity such vessels are enjoying in accordance with the law of the sea; second, the so-called “unidentified vessels” incidents in Japan’s territorial sea in 1999. In addition, the lecture explained the contiguous zone system as an example of a functional concept of sea areas which decides the legal status of sea areas depending on matters. It is different from a “zone” concept of sea areas, which decides the legal status of sea areas depending on physical and geographical location.

【Related Works by Research Director Atsuko Kanehara】

• Atsuko Kanehara, “Refining Japan’s Integrative Position on the Territorial Sovereignty of the Senkaku Islands, International Law Studies, Vol. 97 (2021),
  "Refining Japan’s Position on the Senkaku Islands" by Atsuko Kanehara (usnwc.edu)
• Atsuko Kanehara, “Reconsideration of the Distinction Between the Use of Arms in Law Enforcement and the Use of Force Prohibited by International Law - With an Analysis of the Inherent Significance of This Issue to Japan-,” Japan Review, Vol. 5, No. 2 (2023), pp. 13-48
  https://www.jiia.or.jp/eng/upload/eng/JapanReview_Vol5_02_%20Kanehara.pdf
• Atsuko Kanehara, “The Incident of an Unidentified Vessel in Japan’s Exclusive Economic Zone,” The Japanese Annual of International Law, No. 45 (2002), pp. 116-126
• Atsuko Kanehara, “The Japanese Legal System Concerning Innocent Passage of Foreign Vessels (1990-1998),The Japanese Annual of International Law, No. 42 (1999), pp. 90-110