Book Launch Event: SSU Forum/GraSPP Research Seminar “日本 老いと成熟の平和 (Japan’s Aging Peace)”

On July 1st, the Security Studies Unit (SSU) of the University of Tokyo’s Institute for Future Initiatives hosted a book talk for the Japanese edition of Japan’s Aging Peace (Columbia University Press, 2021), titled Nihon: Oi to Seijuku no Heiwa. The event featured the author, Associate Professor Tom Phuong Le of Pomona College, and was moderated by Associate Professor Naosuke Mukoyama of the Institute for Future Initiatives. Following Prof. Le’s keynote address, Professor Phillip Lipscy (University of Toronto / University of Tokyo Graduate Schools for Law and Politics) and Professor Toshiya Umehara (Hiroshima Peace Institute, Hiroshima City University) joined the discussion, which was followed by a question-and-answer session with the audience.

Keynote Speech
Prof. Le began by posing a question: Why has Japan, surrounded by threats from neighboring countries nuclear North Korea and rising China, not re-militarized to the extent that many international relations theories would predict? The book offers an explanation that Japan’s security policy is shaped by an “antimilitarism ecosystem” composed of material constraints (hardware) and ideational restraints (software).
The primary material constraint (hardware) is Japan’s severe demographic crisis, characterized by an aging and rapidly declining population. This crisis directly impacts the Self-Defense Forces (SDF) by creating a shrinking pool of potential recruits and limiting the financial resources available for significant increases in defense spending. On the other hand, the primary ideational restraint (software) stems from a deeply embedded antimilitarism. This is not a pacifism but a widespread preference for non-military solutions to security problems, shaped by the trauma of World War II. This culture is sustained through peace education, numerous peace museums across the country, and the political legacy of Article 9 of the Constitution. Prof. Le explained that he used the term “ecosystem” because, unlike a “system” that merely defines input-output relationships, he wanted to capture the interactive nature of the hardware and software.
In this respect, the book also distinguishes itself from constructivism, which argues for the causal effect of norms on policy. Prof. Le contends that the ideational restraint of antimilitarism is, in fact, reinforced by the material constraint of population decline.

Discussion and Q&A
Following the keynote, Prof. Lipscy and Prof. Umehara led the discussion. Prof. Lipscy first questioned whether population decline is truly a decisive constraint. He pointed out that European colonial powers succeeded in dominating regions around the world despite being vastly outnumbered. North Korea, though a small nation, has managed to build a formidable military. From this perspective, he suggested that population decline might not be such a critical limitation. Prof. Lipscy also asked whether Japan’s antimilitarism ecosystem remains robust in the face of external shocks, such as Russia’s invasion of Ukraine or a potential Chinese invasion of Taiwan.
Next, Prof. Umehara expressed concern that civilian control, a core norm of Japan’s antimilitarism, is being threatened. He cited instances such as the group worship of SDF personnel at Yasukuni Shrine and the appointment of a former Maritime SDF Vice Admiral as the head priest of the shrine.
Prof. Umehara also re-examined the relationship between population decline and antimilitarism using the case of Kure City in Hiroshima. Kure has a vast tract of vacant land formerly occupied by a Nippon Steel factory. The Ministry of Defense has recently revealed plans to purchase this land to establish a large defense logistics complex. Residents of Kure, who are facing economic stagnation due to population decline, have welcomed the ministry’s plan, anticipating new economic benefits. Prof. Umehara commented that this case might suggest that the material constraint of population decline is not supporting antimilitarism as the book argues, but is instead fueling militarization.
In response, Prof. Le first addressed Prof. Lipscy’s question by stating that North Korea and many European colonial powers were not democracies. Mobilizing people for military purposes is far easier in such regimes compared to a modern democracy like Japan, making a direct comparison difficult. Regarding the impact of external shocks on the ecosystem, he noted that ecosystems change slowly, and thus there is a significant time lag between an external shock and the resulting changes. For example, in response to the threat from China, Japan has embarked on the joint development of a next-generation fighter jet with the UK and Italy. However, its completion is not expected until 2035, illustrating the slow pace at which external shocks translate into policy changes.
Prof. Le then responded to Prof. Umehara’s concerns about a rightward shift among SDF personnel. He argued that even if SDF members and the public lean to the right, it does not immediately weaken the antimilitarist ecosystem. While the number of people with right-wing views may be increasing, they do not necessarily support tax hikes to fund defense spending. There is a difference between calling for military expansion and actually bearing the costs. Politics, he argued, is ultimately about “who gets what, when, and how,” and defense spending still has a low priority compared to other items.
Finally, the floor was opened for questions, leading to a lively discussion among a diverse audience that included foreign correspondents from newspaper companies and graduate students.