Dr. Arnab Dasgupta, Research Analyst, Manohar Parrikar Institute for Defence Studies and Analyses (MP-IDSA), spoke on “Japan’s Territorial Disputes and their Management” at the Monday Morning Meeting held on 03 March 2025. The session was chaired by Ms. Simran Walia, Research Analyst, MP-IDSA. Scholars of the Institute attended the meeting.

Executive Summary

The session provided a comprehensive analysis of Japan’s three key territorial disputes: the Senkaku/Diaoyu Islands with China, Takeshima/Dokdo with South Korea, and the Northern Territories with Russia, which are critical to regional security and international relations. These disputes not only shape Japan’s foreign policy but also influence military dynamics, diplomatic negotiations, and economic interactions in the Indo-Pacific.

Detailed report

In her opening remarks, Ms. Simran Walia provided a historical overview of territorial disputes between Japan and its neighbours, examining their implications for the parties involved. She highlighted how these territorial disputes have contributed to increased military deployments and the securitisation of the region, thereby intensifying geopolitical tensions and strategic competition.

Dr. Arnab Dasgupta opened his presentation with a historical analysis of the three primary territorial disputes Japan has with its neighbours. The three primary territorial disputes are the Senkaku/Diaoyu islands disputes between Japan and China, the Takeshima/Dokdo island dispute between Japan and South Korea and the Northern Territories dispute between Japan and Russia. Japan’s territorial claims over the Senkaku Islands, Takeshima/Dokdo, and the Northern Territories are rooted in historical assertions and post-war treaty negotiations. Japan occupied the Senkaku Islands in 1895, citing a lack of prior ownership, and later regained control in 1972 following their use as a US test range in the immediate aftermath of the Second World War. Tokyo attributes renewed Chinese and Taiwanese claims to the 1969 Economic Commission for Asia and the Far East (ECAFE) report, which highlighted potential resources in the region. Similarly, Japan maintains that Takeshima/Dokdo was historically mapped in the late 16th century and disputes Korean records, asserting that it was legally incorporated into Japanese territory in 1905. Despite US and UK support for Japan’s claim post-WWII, Japan argues that South Korea’s occupation in 1952, following the unilateral imposition of the Syngman Rhee Line, was illegal. Meanwhile, Japan views the Northern Territories as part of Hokkaido’s historical development, emphasising their settlement and economic significance before the Soviet occupation.

In the second segment of his presentation, he examined the current state and characteristics of Japan’s three key territorial disputes: the Senkaku/Diaoyu Islands, Takeshima/Dokdo, and the Northern Territories. These disputes differ in intensity, legal standing, and geopolitical complexity. The Senkaku/Diaoyu dispute remains the most militarised, marked by increasing Chinese military presence, frequent air and sea incursions, and strategic infrastructure placement within Japan’s Exclusive Economic Zone. While the U.S. position had previously been ambiguous, the US – Japan Summit held on 7 February 2025 reaffirmed Washington’s security commitments under Article 5 of the US-Japan Security Treaty, solidifying its stance on defending the islands. Takeshima/Dokdo, under firm South Korean control, is heavily militarised and entangled in historical grievances from the colonial period, with Seoul rejecting arbitration since 2012. Fishing disputes have led to firing incidents, while the US remains ambiguous in its position. The Northern Territories dispute with Russia is in diplomatic deadlock, exacerbated by the impact of the Ukraine conflict and sanctions. It is the only disputed territory with a historical record of permanent residence of Japanese citizens. Russia maintains heavy militarisation and a firm stance on retention through gradual replacement of Japanese residents with Russian residents. Despite US historical support for Japan’s claim, the dispute remains intractable.

In the third segment of his presentation he discussed how Japan has managed these three disputes. Japan’s management of its territorial disputes varies in strategy and intensity across the Senkaku/Diaoyu Islands, Takeshima/Dokdo, and the Northern Territories. In the Senkaku/Diaoyu dispute, Japan maintains a strong armed presence, with the   Japan Coast Guard (JCG), Japan Maritime Self-Defence Force (JMSDF) and Japan Air Self-Defence Force (JASDF) actively countering Chinese incursions. Diplomatically, Japan asserts its position in international forums while restricting access to the islands. In contrast, Japan’s approach to Takeshima/Dokdo is largely diplomatic, with limited effect. Local advocacy efforts, such as Takeshima Day and educational initiatives, aim to sustain Japan’s claim, though differences in commitment between national and regional authorities are noted. The Northern Territories dispute sees significant local activism, including museums, social media campaigns, and past people-to-people exchanges with Russia, which ceased in 2019. However, the growing divergence between Japan and Russia, coupled with military tensions, complicates resolution efforts.

Dr. Dasgupta concluded his presentation with possible future developments in these disputes. Japan’s approach to territorial disputes is shaped by pragmatic considerations, particularly its military limitations. While the United States plays a significant role in Japan’s security strategy, there is considerable scope for Japanese strategic autonomy in managing the Senkaku/Diaoyu Islands and the Northern Territories. The Senkaku/Diaoyu dispute is expected to remain a key flashpoint; however, China has shown signs of accommodation in line with improving Japan-China relations. Additionally, Japan’s emphasis on soft power and people-to-people exchanges, particularly in the Northern Territories and to a limited extent in Takeshima/Dokdo, offers valuable lessons for other nations. The Takeshima/Dokdo dispute exemplifies the importance of securing a ‘first-mover advantage’ in territorial claims.

Questions and Comments

Following the presentation, the floor was opened for questions and comments. Scholars raised inquiries regarding the implications of these disputes on regional stability. Ms. Simran Walia, as the moderator, inquired about the potential impact of international frameworks such as the Quadrilateral Security Dialogue (Quad) on managing Japan’s territorial disputes and the role Japan plays within this framework. Group Captain (Dr.) R.K. Narang (Retd.) raised a question regarding the lessons India could draw from these geopolitical dynamics, specifically comparing the approaches adopted by India and China in managing their disputes to those employed by Japan and China. Additionally, Dr. Mayuri Banerjee enquired about the implications of the recent US commitment to the defence of the Senkaku Islands questioning its strategic significance in signaling to China. She further inquired why such an agreement was introduced at a time when relations between China and Japan appeared to be improving.

Dr. Arnab Dasgupta responded to the comments and the questions raised by MP-IDSA scholars as follows: The Senkaku Islands remain a critical component of the Indo-Pacific security architecture, as they form a key part of the first island chain that regulates access to the Western Pacific and aligns with the core military interests of the United States. Regarding the role of the Quadrilateral Security Dialogue (Quad) in territorial disputes, it was noted that the Quad does not have a direct role in such matters due to its primary focus on providing public goods, including maritime domain awareness, open land networks, healthcare, and connectivity. Given its current framework, the Quad does not engage in bilateral territorial disputes.

In the cases of the Takeshima and Northern Islands disputes, public engagement through people-to-people exchanges and social media has played a significant role. Since Japan has limited political manoeuvrability on these issues, it has opted to bring them into the public domain. This approach presents a potential strategy for India to consider, as raising public awareness and encouraging civic involvement in territorial disputes could facilitate constructive engagement and possible resolutions. Furthermore, while there have been occasional backchannel discussions, formal mechanisms remain lacking due to periodic communication breakdowns between Japan and China. This starkly contrasts with the India-China dispute management approach.

Additionally, the recent commitment by the US is perceived as a strategic signal to both Beijing and Tokyo, emphasising the necessity of operating within defined geopolitical limits. The timing of this aligns with Trump’s broader strategy of encouraging US allies to assume a greater share of their security responsibilities. This shift indicates an expectation for Japan to take a more proactive role in the defence of the Senkaku Islands.

The report was prepared by Ms. Alvina A. Almeida, Intern, East Asia Centre, MP-IDSA.