Navigating Contested Waters (Introduction)

Navigating Contested Waters (Introduction)

by Jonathan W. Greenert
July 29, 2020

This is the introduction to the roundtable “Navigating Contested Waters: U.S.-Japan Alliance Coordination in the East China Sea.”

Events in the South China Sea have attracted the attention of the media, think tanks, and national policy leaders, and rightfully so. The South China Sea is a global economic maritime crossroad with islands and reefs that are the subject of territorial disputes between seven nations and an important regional concern for many more. As such, the sea is of vital interest to the United States. However, in the East China Sea the Senkaku Islands (known as the Diaoyu Islands in China) pose just as salient a security issue. Although Taiwan also officially claims the islands, disputes over the islands primarily involve China and Japan, two of the largest economies and militaries in Asia. Moreover, the proximity of these islands to China and Japan heighten the risk of rapid and unpredictable escalation of crises. Finally, the United States is bound by treaty to support Japan in case of conflict with China, a commitment unlike any it has in the South China Sea.

With these challenges in mind, the National Bureau of Asian Research (NBR) convened a workshop to evaluate the genesis of the territorial disputes in the East China Sea, to review China’s recent strategic and tactical approach to alter the status quo there in its favor, to assess the effectiveness of the U.S.-Japan security alliance and its relevant forces and organizations to deal with the evolving nature of potential crises, and to suggest changes in these organizations’ alignment and cooperation to better prepare the alliance to contain and control provocations and confrontations by China.

To date, Japan has managed the difficult act of navigating increasing tensions between the United States and China. While the alliance with the United States provides security to Japan, China offers Japan considerable economic benefits. The Abe administration has thus far successfully balanced relations between the two great powers, securing the alliance with Washington and engaging with Beijing in multilateral arenas such as trade negotiations and infrastructure development. [1] There have also been several high-level visits between Japan and China since 2018, and before Covid-19 postponed the trip, President Xi Jinping had been scheduled to visit Japan in early 2020. [2] Yet, despite these efforts, tensions in the East China Sea continue to rise.

As a matter of U.S. policy, the Senkaku Islands are covered by the U.S.-Japan Security Treaty because they are under the administrative control of Tokyo. Both China and Japan claim historical sovereignty over the islands, and these claims intersect with nationalist sentiments in both countries. In China, the islands symbolize national pride and historical grievances with Japan; in Japan, citizens fear that China will seize the islands for its own purposes.[3] China reasserted its claim to the Senkaku Islands in the 1970s following reports of abundant natural resources in the East China Sea. Tensions began to simmer in 2012 when the Japanese government purchased three of the disputed islands from a private Japanese owner. Thereafter, China and Japan experienced a wave of nationalist protests, stoked by both governments for domestic political reasons. The protests had the effect of simultaneously elevating tensions in the East China Sea and increasing the political importance of the territorial dispute. [4]

Since 2012, both China and Japan have augmented their military capabilities in the East China Sea. In the last five years, there has been a surge in Chinese incursions into Japanese territorial waters surrounding the islands and the airspace above them. China has also increased the frequency of its air-defense and anti-missile exercises in the East China Sea, as well as conducted regular naval, coast guard, and maritime militia incursions into the waters near the Senkaku Islands. From 2015 to 2019, 65%–70% of China’s incursions sparked a Japanese scramble, and in 2019, over one thousand Chinese vessels entered Japan’s territorial waters or contiguous zone, indicating daily infiltration. [5]

The East China Sea poses a unique set of economic and strategic benefits and challenges. According to the United Nations Convention on the Law of the Sea, a state can claim an exclusive economic zone (EEZ) two hundred nautical miles from its coast.[6] China and Japan have competing and overlapping EEZ claims near the Senkaku Islands, where there are rich fishing grounds and possibly abundant oil and natural gas reserves. The U.S. Energy Information Administration estimates that there are roughly 200 million barrels of oil and 1–2 trillion cubic feet of natural gas in the East China Sea.[7] Additionally, Japan’s Ministry of Land, Infrastructure, Transport and Tourism estimates that the East China Sea holds enough manganese, cobalt, nickel, and natural gas to meet Japan’s needs for hundreds of years.[8] Access to these natural resources is critical for both countries, making it unlikely that either side will acquiesce to the other. Beyond these economic interests, China seeks to restrict access to its EEZ and air defense identification zone, both of which intersect with those of Japan in the East China Sea.

Through facilitating discussions among U.S. and Japanese experts and officials, the NBR workshop explored potential frameworks and concepts to improve bilateral response mechanisms in the East China Sea. One promising option for a new structure to improve coordination emerged from this dialogue: a U.S.-Japan Standing Bilateral Joint Task Force. Such a mechanism would be instrumental for expanding pre-crisis planning between the allies.

This Asia Policy roundtable comprises essays addressing key themes discussed in the workshop. In the first essay, Tetsuo Kotani assesses Chinese military and paramilitary activity in the East China Sea and discusses China’s assertive attempts to disrupt the status quo and establish a new normal in the region. The second essay, written by Admiral (ret.) Tomohisa Takei, evaluates U.S. and Japanese policies in gray-zone scenarios, including a potential conflict around the Senkaku Islands, and provides recommendations to improve joint effectiveness. Building on this analysis of Chinese activity in the East China Sea and the recommendation for a Standing Bilateral Joint Task Force, the third essay by John P. Niemeyer examines the actors involved in a hypothetical gray-zone contingency in the Senkaku Islands and expands on how a joint task force would need to be composed and operate. The roundtable concludes with an essay by Kristine Schenck that addresses the importance of considering China’s response to the creation and existence of such a security structure.

There is much debate within the policy and defense communities regarding the proper solution to improving alliance-led responses in the East China Sea. Against the backdrop of the Abe administration’s unprecedented steps to enhance Japan’s military posture, China’s rapid military advancements, and a renewed U.S. commitment to the security treaty, this series of essays addresses a critical international security challenge and identifies new opportunities for improved coordination in this theater.

Jonathan W. Greenert holds the John M. Shalikashvili Chair in National Security Studies at the National Bureau of Asian Research (United States). Prior to this, he was the 30th chief of naval operations from 2011 to 2015 and served a distinguished 40-year career in the U.S. Navy.


[1] Takashi Shiraishi, “Shinzo Abe Is Redefining Japan’s China Policy for a Generation,” Nikkei Asian Review, February 12, 2020, China-policy-for-a-generation.

[2] “China’s Xi Jinping Postpones State Visit to Japan Due to Coronavirus,” Japan Times, March 5, 2020,; and He Zijia, “A Friend of a Friend: How Better China-Japan Relations Benefit the United States,” Center for Strategic and International Studies, New Perspectives in Foreign Policy, no. 17, April 2019, china-japan-relations-benefit-united-states.

[3] Michael Lipin, “Nationalism Fuels Japan-China Island Dispute,” Voice of America, August 22, 2012,

[4] Ibid.; and Sheila A. Smith, “The History Behind China and Japan’s Anger over a Few Empty Islands,” Atlantic, September 22, 2012,

[5] “U.S.-Japan Coordination and the Challenges Posed by China’s Maritime Activities in the East China Sea,” National Bureau of Asian Research, Workshop, February 19, 2020.

[6] United Nations, “United Nations Convention on the Law of the Sea,” Part 5,

[7] U.S. Energy Information Association, “East China Sea,” September 17, 2014,

[8] Cary Huang, “Diaoyu Islands Dispute about Resources Not Land” South China Morning Post, December 4, 2012, about-resources-not-land.

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