The Development of Japanese Diplomatic History in International Politics in Japan

Masaya INOUE (Keio University)
Diplomatic history is a discipline that originally developed from international law. It
addresses the need to understand the history of diplomatic negotiations in order tounderstand the formation of laws and treaties governing relations among nations.
Meanwhile, international politics, which analyzes relations between nations and theinternational system, is closely linked to diplomatic history. The Japan Association ofInternational Relations (JAIR), founded in December 1956, has also traditionallyemphasized the study of history, as its core members consisted of diplomatic historians1.
Recent years have seen a decline in the study of diplomatic history worldwide.
However, in Japanese international politics, the study of diplomatic history is still of primary
importance. Using statistical data from the JAIR, I aim to summarize current trends in the
study of diplomatic history. First, according to the JAIR’s online member information
management system, 314 of its 2022 members (about 15%) chose Japanese diplomatic
history as their major. In terms of membership, 38 of 153 (25%) were senior members over
the age of 70, while 213 of 1506 (14%) were general members under 70. Members fromyounger generations majoring in diplomatic history appear to be fewer. However, the actual
number of student members (graduate students) majoring in Japanese diplomatic history is
54 out of 286 (18%). This indicates that many of the JAIR’s student members are majoringin Japanese diplomatic history2.
We will also examine the number of papers on Japanese diplomatic history in the
JAIR’s academic journal Kokusai Seiji [International Relations]. Figure 1 summarizes thenumber of articles on Japanese diplomatic history published in Kokusai Seiji over a 60-year
period from 1957 to 2016. Since the 2000s, the number of papers published on the topic has
decreased but maintains a certain percentage. In terms of the number of members and1

Tokushiro Ohata, "Nihon Kokusaiseiji Gakkai 30nen no Ayumi [30 Years of Progress of

the JAIR]," Kokusai Seiji [International Politics], 30th anniversary volume (1986), and Lee,
Jong Won, "Rekishi kara mita Kokusaiseiji Gaku [International Politics from the Perspectiveof History]," Nihon Kokusai Seiji Gakkai eds., Nihon no Kokusaiseiji Gaku [Japan’s study ofInternational Politics], Vol. 4 (Kyoto: Yuhikaku, 2009).
2

Each member can answer up to three fields of study. The survey results are as of July 2018.

published articles, the study of Japanese diplomatic history continues to be a major pillar of
the JAIR today.
Japanese diplomatic history at the JAIR has flourished, which may be due to theselection and concentration of researchers. Many diplomatic historians previously belonged
to the Japanese Society of International Law, and it was not unusual for diplomatic history
papers to be published in Kokusai Ho Gaiko Zasshi [The Journal of International Law and
Diplomacy]. In addition, the Japanese Political Science Association has featured Japanesediplomatic history in Nenpo Seijigaku [The Annuals of Japanese Political Science
Association]. In recent years, however, the number of Japanese diplomatic historians
belonging to both academic societies has been on the decline, and there has been a unipolar
concentration of the study of Japanese diplomatic history in the JAIR. In this article, I will
outline how the study of Japanese diplomatic history has been transformed and developed in
the study of international politics in Japan.
1. Early Years of the JAIR
The study of Japanese diplomatic history has held a special position since the founding of
the JAIR. Hikomatsu Kamikawa, the first president of the JAIR and a former professor at theImperial University of Tokyo, had been involved in compiling Nihon Gaikou Monjo [TheDocuments on Japanese Foreign Policy] for the Ministry of Foreign Affairs (MOFA) before
World War II. Explaining the need to clarify the characteristics of diplomacy in Japan incomparison with that of other countries, Kamikawa said, “In countries outside Europe andthe United States with different religions and civilizations, only Japan has experienced therise and fall of a modern nation-state as well as a modern imperial state, so we must clarify
that there is an aspect unique to our country3.” In the 1950s, when World War II was still
fresh in the public’s memory, examining the course of Japan’s modern diplomacy was not
only a historical study but also a practical exercise linked to the issue of war and peace.
When the JAIR was founded, one of its core missions was the development of the study ofJapanese diplomatic history4.
Although a high standard of monographs on Japanese diplomatic history had been
published since the prewar period, diplomatic documents were not publicly available, andtheir use was limited to a few researchers. After the war, however, the study of Japanese

3

Hikomatsu Kamikawa, "Kindai Kokusaiseiji Shi ni okeru Nihon [Japan in Modern

International Political History]," Kokusai Seiji, Vol. 3 (1957).
4

Katsumi Usui, "Rekishi Kenkyu I [Historical Studies I]," Kokusai Seiji, Vol. 61–2 (1979).

diplomatic history made remarkable progress as diplomatic documents during the prewar
period were released to the public.
It was the Study Group on Japanese Diplomatic History that led the research at thefounding of the JAIR. A workshop was held with Toshio Ueda of the University of Tokyo
serving as secretary from April 1957, and a total of 104 sessions were conducted until
January 1970. Many of the papers on Japanese diplomatic history published in Kokusai Seiji
were based on reports presented at this study group5.
What is noteworthy is the relation between the study group and the MOFA. At thattime in the MOFA, senior archivist Ken Kurihara led the compilation of basic historical
documents, such as Syusen Shiroku [The History of the Japanese End of World War II War ]and Nihon Gaiko Nenpyo narabini Syuyo Monjo [Japanese Diplomatic Chronology andBrief History]. In the MOFA’s Diplomatic Archives, Kurihara trained specialists to compile

The Documents on Japanese Foreign Policy. The study group was initially held within the
MOFA. The study of Japanese diplomatic history developed with deep ties to the MOFA
archives6.
In the early years of the JAIR, Kokusai Seiji frequently featured special issues on
Japanese diplomatic history. For 20 years since the JAIR was founded (from 1956 to 1976),
the organization published an annual special issue on Japanese diplomatic history or
bilateral relations, such as the history of U.S.–Japan relations. This was not only due to theemphasis on historical research but also due to the shortage of researchers in other fields,such as theoretical and area studies, in Japanese international politics. Diplomatic historians
supported early Japanese international politics.
After World War II, Marxist historiography gained influence in historical studies.
In response, the study of Japanese diplomatic history at the JAIR highlighted theclarification of policy decisions based on primary documents. Unlike the Marxist view ofhistory, which emphasizes structural factors, the study of Japanese diplomatic history
developed an elite-centered analysis of the policy process. Under such circumstances, amajor project undertaken by the JAIR was to investigate the causes of the Asia–Pacific War.
Not only researchers but also many Japanese citizens questioned why Japan plunged into a
reckless war. In response, in May 1959, Taiheiyo Senso Gen’in Kyumei-bu [the Departmentof Pacific War Causes Research ] was established within the JAIR. This research department,
led by Jun Tsunoda of the National Diet Library and major Japanese diplomatic historians,

5

Ohata, "Nihon Kokusaiseiji Gakkai 30nen no ayumi."

6

Chihiro Hosoya, "Sosetsu [Review]" Kokusai Seiji, Vol. 61–2 (1979).

conducted joint research with area studies scholars specializing in the United States, theSoviet Union, and China as well as some international political scientists and produced acomprehensive analysis of Japanese diplomacy leading up to the Pacific War. The
culmination of this joint research can be seen in the publication of Taiheiyo Senso eno

Michi [The Road to the Pacific War] by the Asahi Shimbun Sha. To empirically explain
historical facts as well as discover historical materials related to the MOFA and the military,scholars energetically conducted interviews with those involved. The published series
therefor provoked some dispute with Marxist historians, but its pursuit of unravelinghistorical facts was highly appreciated and showed to the world a high standard of the studyof Japanese diplomatic history7.
2. Internationalization of the Study of Japanese Diplomatic History
Since the end of the 1960s, Japanese diplomatic history has also entered an era ofinternationalization. Based on collaborations with overseas academic societies that the JAIR
has promoted since its founding, academic exchanges with overseas researchers became
active. The driving force was Chihiro Hosoya of Hitotsubashi University. The Kawaguchiko
Conference, held in July 1969, was a joint study of diplomatic historians from both Japanand the United States and, as a developed version of The Road to the Pacific War, aimed to
conduct a comparative study of policymaking processes in both countries in the 10-year Far
East crisis from the Manchurian Incident to the attack on Pearl Harbor. This conference led
to the publication of Nichibei Kankei Shi: Kaisen ni itaru 10nen: 1931-1941 [The History of
U.S.-Japan Relations: 10 Years to the Beginning of the War]. The success of this joint
research spurred the promotion of other international research, followed by the publicationof Washington Taisei to Nichibei Kankei [The Washington System and Japan-US Relations]and Nichiei Kankei Shi: 1917-1949 [The History of Anglo-Japanese Relations: 1917-1949],
which internationally showcased the achievements of the study of Japanese diplomatic
history8.

7

Nihon Kokusaiseiji Gakkai Taiheiyo Senso Gen’in Kyumei bu eds. Taiheiyo Senso eno

Michi [The Road to the Pacific War], 8 Volumes. (Tokyo: Asahi Shimbun Sha, 1962–3).
8

Chihiro Hosoya, Makoto Saito, and Seiichi Imai eds., Nichibei Kankei Shi: Kaisen ni itaru

10 nen : 1931–1941 [The History of U.S. –Japan Relations: 10 Years to the Beginning of theWar], 4 volumes. (University of Tokyo Press, 1971–2); Chihiro Hosoya and Makoto Saito
eds., Washington Taisei to Nichibei Kankei [The Washington System and Japan–US
Relations], (University of Tokyo Press, 1978); and Chihiro Hosoya eds., Nichiei Kankei Shi

Research themes in Japanese diplomatic history have also changed with theprogress of internationalization. In the early years of Kokusai Seiji, many papers focused onJapanese foreign policy, but their attention gradually shifted from one-nation diplomacy tothematic history and the international history that analyzed bilateral relations. This led to a
decline in the chronological study of Japanese diplomatic history. The research approachalso transitioned from the traditional approach, which analyzed the policymaking process of
top government officials, to the nontraditional approach, which focused on informal actors,
public opinion, and interest groups. The study of Japanese diplomatic history, which until
then had been biased toward analyzing trends among the government elite, expanded its
analysis scope to include diverse actors such as the military, congress, private organizations,mass media, and intellectuals. Kokusai Seiji also began featuring issues devoted to researchthat delved into the role of informal actors and examining the intersection between
diplomatic history and financial and economic history by focusing on the role of businessleaders.
3. Japanese Diplomatic History and Theoretical Studies
When considering the development of the study of Japanese diplomatic history, theinfluence of American modern political theories and behavioral science approaches cannot
be ignored. The 1970s saw a growing movement to use the theoretical analytical frameworkof foreign policy as a historical narrative of Japanese diplomatic history. Specifically, studies
began to analyze examples from Japanese diplomatic history by invoking Richard Snyder’sframework for analyzing the foreign policymaking process and Graham T. Allison’sorganizational process model9. In addition, based on the theory of linkage politics, recent
studies adopted the perspective of the linkage between domestic and foreign affairs and therivalry and coordination of domestic groups in shaping foreign policy into historicalnarratives.
Of course, Japanese diplomatic history was not unilaterally influenced by Americaninternational political theory. As argued by diplomatic historian Tetsuya Sakai, the study ofmodern Japanese diplomatic history was originally less about the history of bilateral relations
as opposed to that of Western countries and more about the policymaking analysis of one

1917–1949 [The History of Anglo–Japanese Relations: 1917–1949] (University of Tokyo
Press, 1982).
9

Graham Allison. Essence of Decision: Explaining the Cuban Missile Crisis, 1ed. (Boston:

Little Brown, 1971).

country. In addition, compared with studies of diplomatic history in Western countries,
which clearly distinguish between domestic politics and diplomacy, Japanese diplomatic
history has traditionally incorporated the interaction between domestic and foreign affairs
into its analytical perspectives. Indeed, in international relations theory, transnationalism,
which focuses on the role of nonstate actors, became popular from the late 1970s, but suchan approach has long been common in studies of Japanese diplomatic history. In this sense,
rather than accepting the latest American theory, Japanese diplomatic history can be said tohave “rediscovered” the strengths of its own research within the American theory approach.
The policymaking process theory in international politics originally had a high affinity withJapanese diplomatic history10.
Meanwhile, there was also an attempt to present a new theoretical model of thepolicymaking process from the study of Japanese diplomatic history. From the perspective ofmodern Japanese diplomatic history, Chihiro Hosoya argued that Japan’s policymaking
model, after the collapse of the oligarchy model in the Meiji period, became a “cone-shaped
system” in which the “middle echelon” within the military and the bureaucracy became thereal players in policymaking because of the lack of top-level policy coordination. After WorldWar II, he asserted, this system transformed into a “tripod system” in which political leaders,
led by the prime minister, make policy decisions with the Liberal Democratic Party, thebureaucracy, and the business community as advisory groups11.
However, outside Hosoya’s work, there has been little active exploration of a newtheory of the policymaking process in modern Japanese diplomatic history. Historians
interested in individual events have been willing to explain historical events using the theory
but have not been keenly interested in theory-building.
The theorization of the policymaking process had more affinity with the analysis of
postwar Japanese diplomacy. This is because, in the 1970s, most Japanese diplomaticrecords of the postwar period remained classified, and the policymaking process was in a
black box. Japanese international political scientists, educated in U.S. graduate schools, used
the policymaking process theory to conduct case studies of Japanese diplomacy regarding

10

Tetsuya Sakai, Kindai Nihon no Kokusai Chitsujo Ron [Theory of International Order inModern Japan], (Tokyo: Iwanami Shoten, 2007) 4–5.
11

Chihiro Hosoya and Joji Watanuki eds., Taigai Seisaku Kettei Katei no Nichibei Hikaku [AComparison of the Process of Foreign Policy Making between Japan and the United States](University of Tokyo Press, 1977); Akio Watanabe, “III Riron Kenkyu 2 [III: Theoretical
Studies (Part 2)],” Kokusai Seiji, vol. 61–2 (1979).

the Okinawa reversion negotiations and the U.S.–Japan trade friction12.
4. Development of Postwar Diplomatic History Studies
In the 1960s, the use of primary documents in various countries to reconstruct the history ofinternational relations began to spread in the United States. Even in Japan, research
conducted with this multiarchival approach has been around since the 1950s13. However, it
was not until the 1970s, when it became easier for Japanese to travel abroad, when themultiarchival approach became widespread among Japanese researchers.
The multiarchival approach to Japanese diplomatic history began with the study ofthe occupation period from 1945 to 1952. As Britain and the United States declassified theirdiplomatic records one by one, Japanese historians began actively collecting documents inWashington and London in the 1970s and dramatically developed occupation studies.
Following the study of the occupation period, empirical research based on primary
documents also progressed regarding the origins of the San Francisco Peace Treaty and the
U.S.–Japan Security Treaty14.
The declassification of Japanese diplomatic records on postwar Japan was anotherfactor that encouraged occupation studies. In May 1976, the MOFA’s Diplomatic Archives
began opening its postwar diplomatic records to the public, which made it possible toanalyze postwar history with Japanese documents. Nevertheless, the level of declassificationof diplomatic records in Japan was still far below those of the United Kingdom and theUnited States. Therefore, those who wanted to study postwar Japanese diplomacy first had
to investigate the American and British archives.
The mainstream of prewar Japanese diplomatic history has been Japan’s policy on

12Haruhiro Fukui, Jiyu Minshuto to Seisaku Kettei [Liberal Democratic Party and Policy

Making], (Tokyo: Fukumura Publishing, 1969); I.M. Destler and Hideo Sato eds., Copingwith U.S.–Japanese economic conflicts. (Lanham, MD: Lexington Books, 1982).
13

See. Chihiro Hosoya, Siberia Shuppei no Shiteki Kenkyu [A Historical study of theSiberian Intervention] (Kyoto: Yuhikaku, 1955).
14

Okurasho Zaisei Shi Shitsu eds., Showa Zaisei Shi: Shusen kara Kowa made (3) America

no Tainichi Senryo Seisaku [Showa Financial History: From the End of the War to the Peace(3) U.S. occupation policy toward Japan] (Tokyo: Toyo Keizai, Inc., 1976); Makoto Iokibe,

Beikoku no Nihon Senryo Seisaku [U.S. occupation policy toward Japan], 2 volumes(Tokyo: Chuokoron Sha, 1985); and Chihiro Hosoya, San Francisco Kowa eno Michi [TheRoad to the San Francisco Peace Treaty] (Tokyo: Chuokoron Sha, 1984).

the Chinese continent and its relations with China, but in the study of postwar diplomatic
history, the history of U.S.–Japanese relations has become popular partly because of
America’s active disclosure of historical documents. In parallel with the progress in the studyof the history of postwar U.S.–Japanese relations, the study of Cold War history byinternational political scientists also flourished in Japan. The achievements of Cold War
studies and the primary documents that were declassified in the United States haveadvanced the study of postwar Japanese diplomatic history.
In contrast to postwar U.S.–Japan relations, however, other bilateral relations havestagnated partly because of delays in Japan’s declassification of its diplomatic records. In the
1990s, some researchers conducted empirical studies on Japan’s relations with South Korea,
China, and the Soviet Union mainly using diplomatic records from the United States andBritain15.
In the early 21st century, the situation surrounding Japanese diplomatic records
significantly changed. First, the Administrative Document Information Disclosure Act was
enforced in 2001. Under the law, diplomatic historians could request disclosure of
diplomatic documents from the MOFA. Additionally, the 2010s saw an improvement in the
MOFA’s document management, and many diplomatic records were transferred to the
Diplomatic Archives. These institutional reforms widened the scope of Japanese diplomatic
history, which had depended on the archives of the United States and Britain and led to theemergence of a series of studies on Sino–Japanese and Japan–Korea relations.
Japan’s change of government in 2009 also greatly improved the situation
surrounding postwar diplomatic history. The administration of the Democratic Party ofJapan launched a commission to investigate secret agreements in postwar U.S.–Japan
relations. Through this investigation, the MOFA declassified diplomatic records onnegotiations to revise the U.S.–Japan Security Treaty in 1960 and the return of Okinawa in
1972, which have long been classified. This allowed for an analysis of the history of postwar
relations between Japan and the United States from primary documents on both sides. The
study of postwar Japanese diplomatic history, published in the 2010s, used a combination of

15

Takahiko Tanaka, Nisso Kokko Kaifuku no Shiteki Kenkyu [A Historical Study of theSoviet – Japanese Normalization], (Kyoto: Yuhikaku, 1993); Lee, Jong Won, Kan’nichi
Seijoka no Seiritsu to America, 1960–65 [Normalization of Korea and Japan and the UnitedStates, 1960 to 65], Kindai Nihon Kenkyu [Annual Modern Japanese Studies], Vol. 16(1994); and Chen Zhaobin, Sengo Nihon no Chugoku Seisaku [Japan’s China Policy in
Postwar] (University of Tokyo Press, 2000).

historical documents from multiple countries and oral histories to describe the policymaking
process in detail and examined how the relationship between politicians and bureaucrats
transformed over the formation of foreign policy.
5. The Future of the Study of Japanese Diplomatic History
How will the study of Japanese diplomatic history develop in the future? A recent notable
trend is the shift in research themes from prewar to postwar. From 2012 to 2016, nearly
90% of articles on Japanese diplomatic history published in Kokusai Seiji discussed postwar
diplomacy. In the field of prewar studies, the classical analysis of the policymaking process ison the decline, but more studies have recently focused on diplomatic initiatives and ideas of
specific individuals. In fact, the study of Japanese diplomatic history, which probes the
personalities and external perceptions of political, military, and opinion leaders, has a long
history in academic circles16. Based on these traditions, recent studies can be considered
attempts to bridge the history of diplomacy and political thought.
Furthermore, in recent years, the connection with global history has been
attracting attention. Japanese diplomatic history, which has traditionally focused ontransnational actors, has shifted its focus from power games among sovereign states to theanalysis of the flow of people, goods, and money. The question for future research is how tosituate the micro analysis of the policymaking process, which has been the specialty ofJapanese diplomatic history research, in the context of global history.
In the 2010s, a full-fledged study of diplomatic history on the return of Okinawa
and the Sino–Japan normalization was published. Recently, the 1970s and 1980s, during
which the international community developed interdependence, have become the subject of
diplomatic history. To describe “economic diplomacy,” which highlights the involvement of
the Ministry of Finance and the Ministry of International Trade and Industry in foreign
affairs, scholars will be required to adopt a different analytical approach from the traditional
method of tracing policymaking processes.
The issue of historical perceptions, which has existed since the 1980s, is anothercritical issue in the study of diplomatic history. Ways to remember and recount the pastcannot be clarified only through a conventional analysis of the policymaking process.
Nationalism and identity in a nation’s foreign actions are important research topics inJapanese diplomatic history.
As discussed above, Japanese diplomatic history has reflected theories of

16

See. Akira Irie, Nihon no Gaiko [Diplomacy of Japan] (Tokyo: Chuokoron Sha, 1966).

international politics in its historical narratives. However, compared with the 1970s, when
historians were actively learning theories of international politics, recent years havewitnessed less mutual exchange owing to the fragmentation of historical and theoreticalstudies. As a result, historical researchers have fewer opportunities to confront theory.
Another issue is globalization. While Japanese diplomatic history research has
reflected the latest overseas research and historical materials, it has not actively published its
findings abroad. As a result, the latest research results on Japanese diplomatic history havenot been fully reflected in research conducted by English-speaking countries. Futurescholarly efforts would require a strengthened dissemination of research on Japanesediplomatic history abroad.
Figure 1 Number of articles on Japanese diplomatic history published in

Kokusai Seiji (Aggregated by the author)
60

50
40
30
20
10
0

1957- 1962- 1967- 1972- 1977- 1982- 1987- 1992- 1997- 2002- 2007- 20121961 1966 1971 1976 1981 1986 1991 1996 2001 2006 2011 2016

Postwar

1

0

0

8

7

9

13

14

27

16

22

24

Prewar

54

39

35

13

21

24

17

19

12

17

9

3