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Keio Professor Yuichi Hosoya: Japan-US-South Korea Cooperation is the 'Final Piece' in Abe's Security Vision

Professor Yuichi Hosoya discusses how the landmark agreement at the recent Camp David trilateral completes Shinzo Abe's vision for a Free and Open Indo-Pacific.



Prime Minister Fumio Kishida, US President Joe Biden, and South Korean President Yoon Suk-yeol pose for a photo ahead of the Japan-US-South Korea summit at Camp David on August 18. (©Kyodo)

In an interview with The Sankei Shimbun and JAPAN Forward, Yuichi Hosoya, a professor of international politics at Keio University, explains the significance of the Japan-United States-South Korea summit meeting on August 18.

The leaders of the three countries reached a landmark agreement during the summit. Professor Yuichi Hosoya explains, "The United States 'chained together' Japan and South Korea so that they would not sit idly by in the event of a Taiwan contingency."

He continues, "Without a doubt, the center of gravity of trilateral cooperation has shifted from the traditional responses to North Korea to the realization of a Free and Open Indo-Pacific [FOIP]."

Professor Yuichi Hosoya

Taiwan Contingency

In the agreement, the leaders of Japan, the United States, and South Korea referred to the Indo-Pacific before mentioning North Korea. According to Hosoya, the biggest concern for the US in the region right now is a possible Taiwan contingency. He also believes that the effort to shift focus to that issue was already underway. This is shown by the confirmation of the "importance of maintaining peace and stability across the Taiwan Strait" in the joint statement issued during the trilateral summit meeting in Cambodia in November 2022.

Furthermore, at the recent summit in Washington DC, the leaders of the three nations added a call for "peaceful resolution of cross-Strait issues."

Professor Hosoya believes that the statement "signifies opposition to the armed unification of Taiwan by China, and is the first time that leaders of these three countries have unanimously expressed this position."

He further explains that the statement makes "deterring a Taiwan contingency a common strategic goal and establishes security cooperation among Japan, the US, and South Korea as an important means to achieve that goal."

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Prime Minister Fumio Kishida shakes hands with South Korean President Yoon Suk Yeol at Phnom Penh, Cambodia on November 13, 2022. (©The Cabinet Public Relations Office)

Commitment to Consultation

However, Professor Hosoya highlights that the most important point of agreement was the "commitment" of the three leaders to consult among themselves. By doing so, they will be able to coordinate their responses to "regional challenges, provocations, and threats" that affect their collective interests and security. According to Hosoya, the possibility of a Taiwan contingency was uppermost on their minds when the agreement was made.

However, the content of such consultations among Japan, the US, and South Korea within this framework appears to be somewhat limited. It would be confined to sharing information and coordinating external messaging. 

Therefore, the meaning is different from the consultation system as a prelude to invoking the right of collective self-defense, as stipulated by the North Atlantic Treaty Organization (NATO). "In this case, each country will be free to determine its actual actions," the Professor explains.

Originally, coordination of responses to a Taiwan contingency was strongly urged by the administration of US President Joe Biden. According to Hosoya, the United States believed that if a "Taiwan contingency" was to be considered a "Japan contingency," then at the very least Japan should not be allowed to evade involvement by doing nothing whatsoever. 


Japan has been left some discretionary leeway "probably due to deference to South Korea, which has developed little awareness of the impact a Taiwan contingency would have on its own national security," Hosoya explains.

Chinese warship Luyang III sails crosses in front of the US destroyer USS Chung-Hoon in the Taiwan Strait on June 3, 2023. (US Navy/Mass Communication Specialist 1st Class Andre T Richard/Handout via REUTERS)


Professor Hosoya describes the Japan-US-South Korea summit meeting as "truly groundbreaking," because it called for a wide range of cooperation. This includes regular summit meetings and joint exercises. "The US ideal of an Indo-Pacific strategy has at last become reality," he declares.

The United States no longer has sufficient deterrence capabilities on its own, due to the rapid expansion of Chinese military power. According to Professor Hosoya, the US is attempting to bolster cooperation among allies by promoting "integrated deterrence" with its allies playing more important roles. 

The United States has also developed the Quad arrangement with Japan, Australia, and India and the AUKUS arrangement with the United Kingdom and Australia. "These schemes represent attempts to strengthen the strategic defense perimeter," the Professor says.

The Missing Link

Hosoya explains that after these ties had been forged, the missing link in the US strategy was Japan-South Korea relations because of the stubborn bilateral frictions. He adds, "There is no denying that South Korea is extremely important in terms of the size of its military and its geostrategic position." 

After the agreement was reached, President Biden quipped, "If I seem happy, that's because I really am happy." Hosoya says that the joy the president projected shows how committed he was to making the agreement a reality. 

Prime Minister Fumio Kishida and South Korean President Yoon Suk-yeol shake hands on the sidelines of the NATO Summit. In Vilnius on July 12. (Cabinet Office of Japan.)

A Dramatic Shift

The trilateral agreement marked a major shift for South Korea as well. Professor Hosoya expounds, "Its previous approach was limiting the threat from North Korea while pursuing equidistant diplomacy vis-a-vis the United States and China."

For the past quarter century, South Korea has tried to eliminate the North Korean threat and promote reconciliation and unification with the North based on friendship with China. 

But the scenario of a regional order based on expectations that China, as chair of the six-party talks on North Korea, would be actively involved in regional stability and otherwise display goodwill has collapsed. "And South Korea's previous strategy collapsed along with it," Hosoya explains.

South Korean President Yoon Suk-yeol has opted instead to emphasize ties with Japan and the United States as fellow members of the democratic camp. Despite the domestic outcry over the so-called "wartime labor lawsuit," his administration presented a proposal to resolve the issue. It basically respected Japan's position and otherwise prioritized the improvement of Japan-South Korea relations.

Shinzo Abe's Vision

Professor Yuichi Hosoya says that there are concerns about the "sustainability" of the Japan-US-South Korea agreement. But he also adds that considering the structural shift in the security environment in Asia, South Korea is not likely to return to "a strategy that relies on China's goodwill." 

Needless to say, the trilateral agreement is of tremendous significance for Japan. But for this agreement to become a reality, "Japan first needed to be trusted internationally," Hosoya points out.

The late Prime Minister Shinzo Abe in an interview with The Sankei Shimbun at the Diet on March 25, 2022. (©Sankei by Yasuhiro Yajima)

The starting point was former Prime Minister Shinzo Abe's August 2015 talk concerning historical awareness. Hosoya says that Abe "demonstrated sound historical understanding and built trust toward Japan." Then, the following year in 2016, Abe proposed his vision of a Free and Open Indo-Pacific (FOIP).

Professor Hosoya concludes, "The final piece required to achieve Abe's vision of a new strategic order has now been filled in, thanks to President Yoon's courage and the signing of this agreement."


(Read the article in Japanese.)

Interview by: Hideo Miyashita

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