A Review of the Autonomy-Security Trade-off Model:
The Case of Japan's Behavior in the Asymmetric Alliance with the United States 1
Isao MIYAOKA
Keio University
Introduction
Although there are several theories of asymmetric relations, 2 it is worth reconsidering theautonomy-security trade-off model of alliance behavior, which James Morrow advocated in
1991, 3 for three reasons. First, the model is a typical mainstream theory concentrating on major
powers like the United States and paying little attention to minor powers like Japan. Second,
the model nicely captures the essence of the traditional Japan-U.S. Alliance, that is, what
Sakamoto Kazuya calls an "asymmetric mutuality" between Japan's offer of bases and the U.S.
offer of forces, 4 while it also contradicts Japan's recent behavior in the asymmetric alliance with
the U.S. Third, although many scholars have examined the asymmetry of the Japan-U.S.
Alliance, 5 most of them do not focus on the model. 6 Although there are a few exceptions, such
as Mayumi Itayama's book and Jongsung Lee's doctoral dissertation, the former covers theperiod until 1978, and the latter concentrates on Japan's autonomy in a broader sense. 7
This paper draws three theoretical implications regarding the autonomy-security tradeoff model from the history of Japan's asymmetric alliance with the U.S. First, the concept ofasymmetric alliances should include a symmetric dimension when applied to U.S. alliances
after World War II. Second, a junior partner may strengthen its security contributions to its
senior partner by increasing its military spending and expanding the scope of defense
cooperation. Third, a junior partner may continuously make autonomy concessions, irrespectiveof changes in its security contributions to the senior ally. The following of this paper elaborates
on these implications in turn.

1

1. The Concept of Asymmetric Alliances
Morrow advocates the autonomy-security trade-off model in his 1991 article. It is presented as
an alternative to the capability aggregation model of symmetric alliances, based on a balanceof power theory. Morrow compares asymmetric and symmetric alliances in terms of formationand duration (or dissolution). As an empirical test, he conducts a statistical analysis of 164
alliances formed between 1815 and 1965.
Morrow considers alliances asymmetric when "one ally gains security and the otherautonomy." 8 It is noted here that although this definition is based on asymmetries in benefits
that the parties receive from the alliance, Morrow also admits that "asymmetries in capabilities
are generally found in asymmetric alliances." Thus, he writes that "the minor power will makeautonomy concessions to the major power in return for the security the major power can
provide." 9 According to Morrow, "[s]ecurity benefits arise primarily from the militarycapabilities of an ally," 10 and autonomy benefits could include military bases for the projectionof power and control over an ally's foreign and domestic policies. 11
Morrow's concept of asymmetric alliances is too narrow for U.S. alliances after theSecond World War. He assumes that what the minor power provides to the major power isautonomy only. In practice, however, the U.S. has expected its junior allies to contributeautonomy and security. The U.S. Senate's Vandenberg Resolution of 1948 has required the U.S.
Government to make its military allies act on the principle of "continuous and effective selfhelp and mutual aid." 12 Therefore, the concept should be broadened to include a symmetricdimension, an exchange of security benefits, when applied to U.S. alliances after World War
II. 13
In Morrow's 1991 article, post-war Japan is categorized as a minor power. This
categorization is appropriate for Japan from the 1940s to the 1960s. First, it was reborn with aconstitution to limit its use of force. Article 9 of Japan's 1946 Constitution prescribes the2renunciation of war, the prohibition of war potential, and the denial of the state's belligerency
right. Second, following this spirit of the peace constitution, the Japanese Government
adopted the so-called "Yoshida Doctrine," which attached great importance to light armamentand economic development by relying on the U.S. for the security of Japan.
Third, the Japan-U.S. Security Treaty of 1960 explicitly codified an asymmetric natureof the Japan-U.S. Alliance. Article 5 of the treaty stipulates the collective defense of Japan intime of its contingency: "Each Party recognizes that an armed attack against either Party inthe territories under the administration of Japan would be dangerous to its own peace andsafety and declares that it would act to meet the common danger in accordance with its
constitutional provisions and processes." 14 Article 6 stipulates the use by the U.S. forces of
military bases in Japan: "For the purpose of contributing to the security of Japan and themaintenance of international peace and security in the Far East, the United States of America
is granted the use by its land, air and naval forces of facilities and areas in Japan."
Nevertheless, the Japan-U.S. Security Treaty also contained the seeds of a symmetricaspect of the Japan-U.S. Alliance. Article 3 writes, "The Parties, individually and incooperation with each other, by means of continuous and effective self-help and mutual aid
will maintain and develop, subject to their constitutional provisions, their capacities to resist
armed attack." This article reflects the principle of "continuous and effective self-help andmutual aid" in the Vandenberg Resolution of 1948.
Defense cooperation of the current Japan-U.S. Alliance consists of two layers (see Table
1-1). In an asymmetric layer at the alliance's substructure, Japan offers military bases, while theU.S. provides strike capabilities and nuclear deterrence. In a symmetric layer, Japan and the
U.S. offer defense and logistics capabilities, depending on a contingency situation. In total,
Japan gains security, while the U.S. gains autonomy and security. Article 9 of Japan'sConstitution helps maintain the asymmetric layer. Still, it is worth noting that many other junior3

partners also rely on the strike capabilities and nuclear deterrence the U.S. offers.

Table 1-1: Symmetric and asymmetric exchanges of different benefits
The U.S.
S: Defense capabilities
S: Logistics capabilities
Asymmetric layer
S: Strike capabilities
S: Nuclear deterrence
Note: "S" and "A" respectively stand for security and autonomy benefits offered by Japan or
the U.S.
Symmetric layer

Japan
S: Defense capabilities
S: Logistics capabilities
A: Military bases

2. Changes in Security Benefits from a Junior Partner
Although Morrow discusses and analyzes the impact of changes in capabilities on the break-up
of alliances, 15 he ignores changes in minor power capabilities. 16 He implies this when he
explains one of the two reasons why asymmetric alliances are likely to last longer thansymmetric alliances.
[C]hanges in the weaker power's capabilities will not greatly alter the nature of the trade.
Because it provides autonomy to the major power, its contribution to the alliance isunaffected by changes in its capabilities. Its security is primarily provided by its major
power ally, so its benefits from the alliance will not change greatly with changes in its
capabilities. Consequently, these shifts in capabilities are unlikely to break the alliance.
In a symmetric alliance, a change in either ally's capabilities forces a reallocation of thebenefits of the alliance, making the alliance less likely to persist. 17
Morrow underestimates the impact of changes in minor power capabilities on alliances. A juniorpartner may strengthen its security contributions to its senior partner by increasing its militaryspending and expanding the scope of defense cooperation. Post-war Japan is a case in point,
although it has been restricted by its Peace Constitution.
First, there has been an increasing trend in Japan's military expenditure over the past six
decades. Japan's military spending has been rising since the 1960s except for the 2000s (see4

Figure 2-1).

6E+12

2E+12
0
1955
1958
1961
1964
1967
1970
1973
1976
1979
1982
1985
1988
1991
1994
1997
2000
2003
2006
2009
2012
2015
2018

trillion yen

4E+12

financial year
Figure 2-1: Change in Japan's military expenditure in local currency
Source: Stockholm International Peace Research Institute, "Data for all countries 1949–2020,"
SIPRI Military Expenditure Database, https://www.sipri.org/databases/milex (accessed
February 18, 2022).
Second, Japan has expanded the geographical and legal scope of defense cooperation
with the U.S. in the past four decades, mainly by revising the Guidelines for U.S.-Japan Defense
Cooperation (hereafter referred to as "Guidelines") and by enacting legislation for
implementing the Guidelines.
The 1978 Guidelines focused on "actions in response to an armed attack against
Japan." 18 From the late 1970s to the 1980s, Japan contributed to the security of the
U.S. by strengthening its defense capabilities for the defense of Japan, which wascritical to preventing Soviet troops from advancing into the Pacific Ocean.



The 1997 Guidelines introduced "cooperation in situations in areas surrounding
Japan that will have an important influence on Japan's peace and security." 19 In 1999,
Japan's Diet passed the Law Concerning Measures to Ensure the Peace and Securityof Japan in Situations in Areas Surrounding Japan, which authorizes the Japan SelfDefense Forces (JSDF) to engage in logistical support and search and rescue
5

operations in adjacent conflict situations.


The 2003 Koizumi-Bush Talks used the expression "the Japan-U.S. Alliance in the
global context." In the Global War on Terror led by the U.S. in the 2000s, Japan
dispatched the JSDF to the Indian Ocean and Iraq for logistical support to foreign
forces and humanitarian and reconstruction assistance.

In July 2014, the Cabinet partially accepted the exercise of the right of collective
self-defense. 20 The 2015 Guidelines added a new section titled "Actions in Responseto an Armed Attack against a Country other than Japan" and expanded theircooperation to the new domains of space and cyberspace. 21

In short, Japan has strengthened its security contributions to the U.S. by increasing its militaryspending and by expanding the scope of defense cooperation.

3. Changes in Autonomy Benefits from a Junior Partner
Examining the long-term relationship between security and autonomy provided by a juniorpartner is necessary. In the case of the Republic of Korea, there is an argument that "the growing
national power of a weaker state might encourage the state to reclaim some of the autonomy it
had ceded to a stronger state for the sake of the alliance." 22 In contrast, the case of post-war
Japan indicates that a junior partner may continuously make autonomy concessions,irrespective of changes in its security contributions to the major power.
First, although the total area of the military bases for U.S. Forces in Japan (or USFJ)
sharply declined in the 1950s, the area did not significantly change between the mid-1970s andthe mid-2010s (see Figure 3-1). Although Okinawa was reverted to Japan in 1972, most of thevast U.S. military bases in the prefecture have remained since then. A recent slight drop is dueto the return of a significant portion of the Northern Training Area in Okinawa in 2016.

6

area (km2)

1,500,000
1,000,000
500,000

1955
1958
1961
1964
1967
1970
1973
1976
1979
1982
1985
1988
1991
1994
1997
2000
2003
2006
2009
2012
2015
2018

0
year
Figure 3-1: Changes in the area of the USFJ bases in Japan
Source: Asagumo shinbunsha, ed. Bōei handobukku [Handbook for defense] (Tōkyō: Asagumo
shinbunsha, 1989, 2020).
Second, there is an increasing trend of the USFJ-related costs paid by the Japanese
Government except in the 2000s (see Figure 3-2). Host Nation Support (HNS) is the costsharing for the stationing of USFJ, which started in 1978. In 1997, the Japanese Government
also began to pay for the costs related to the 1996 Final Report compiled by the Special Action
Committee on Okinawa (SACO). HNS peaked in 1999 and has been on the decline since then.
Nevertheless, U.S. Forces realignment-related expenses have been on the rise since 2007. The
USFJ-related costs shown here don't include those stipulated in the Japan-U.S. Status of Forces
Agreement of 1960, such as rent for facilities.

7

5000
3000
2000
1000
0
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020

hundred million yen

4000

year

Host Nation Support
The cost for SACO-related projects
U.S. Forces realignment-related expenses

Figure 3-2: USFJ-related costs
Source: Japan Ministry of Defense, "Zainichi beigun chūryū keihi hutan no suii" [Changes incost sharing for the stationing of USFJ,"
https://www.mod.go.jp/j/approach/zaibeigun/us_keihi/suii_img_r03.pdf(accessed February 20, 2022).
Conclusion
This paper draws three theoretical implications regarding the autonomy-security trade-offmodel from the history of Japan's external relations with the U.S. First, the concept ofasymmetric alliances should include a symmetric dimension when applied to U.S. alliances
after World War II. Second, a junior partner may strengthen its security contributions to its
senior partner by increasing its military spending and by expanding the scope of defense
cooperation. Third, a junior partner may continuously make autonomy concessions, irrespectiveof changes in its security contributions to the major power.
Japan's increasing security contributions have not led to its lower autonomy concessions.
It is possible to think of three reasons for this long-term trend: 1) the increasing overall missionsof the Japan-U.S. Alliance, 2) the U.S. anxiety that once a military base in a foreign country is
relinquished, it will be difficult to re-acquire it, and 3) the bifunctionality of military bases.
8

The last possible reason needs a supplementary explanation. The bifunctionality of
military bases means that USFJ increases not only the U.S.'s autonomy but also Japan's
security. 23 Japan's Defense White Paper 2021 writes: "Under the Japan-U.S. Security
Arrangements, the presence of USFJ functions as deterrence, while on the other hand, given theimpacts of the stationing of the USFJ on the living environment of the local residents, it isnecessary to make efforts appropriate for the actual situation of each area in order to mitigate
the impacts." 24 The Japanese Government regards USFJ as a "tripwire" 25 for the automatic U.S.
involvement in the war. Military bases offer security benefits to a host country as well.
Further research is needed to develop these implications and speculation into new
hypotheses and to test them against the U.S. security relations with Japan and its other allies,
such as the Republic of Korea. 26
1This paper is based on the author's presentation titled "Japan's Alliance Behavior as a JuniorPartner: An Analysis from the Perspective of Asymmetry" at the virtual partner organization
roundtable "What Theoretical Implications Can Be Drawn from Japan's External Relations?"
held at the 2022 Annual Convention of the International Studies Association (ISA) on March
29th, 2022. The author expresses his gratitude to the Japan Association of International
Relations (JAIR) for inviting me to join the roundtable and financially supporting me toparticipate in the ISA convention. He is also grateful to Professor Paul Midford for his
valuable comments on my presentation.
2

For example, David Lake discusses five types of security relationships along an anarchy-hierarchy continuum. Alliance is one of them. In his discussion, alliance lies at the anarchic endof the continuum. Alliance partners are considered to retain full decision-making authority.
Lake says that the U.S. opted for anarchic alliance-based relations. On the other hand, his"residual control" concept may help analyze the Japan-U.S. Alliance. David A. Lake, "Anarchy,
Hierarchy, and the Variety of International Relations," International Organization 50, no. 1
9(Winter 1996): 1-33; and David A. Lake, Entangling Relations American Foreign Policy in Its
Century (Princeton, NJ: Princeton University Press, 1999).
3

James D. Morrow, "Alliances and Asymmetry: An Alternative to the Capability Aggregation

Model of Alliances," American Journal of Political Science 35, no. 4 (November 1991): 904933.
4

Sakamoto Kazuya, The Bonds of the Japan-U.S. Alliance: The Japan-U.S. Security Treaty

and the Search for Mutuality, trans. The Japan Institute of International Affairs (Tokyo: Japan
Publishing Industry Foundation for Culture, 2022), 9.
5

The English-language literature on the asymmetry of the Japan-U.S. Alliance in English

includes Misato Matsuoka, Hegemony and the U.S.-Japan Alliance (London: Routledge,2018); and Matteo Dian, The Evolution of the U.S.-Japan Alliance: The Eagle and theChrysanthemum (Oxford: Chandos Publishing, 2014). On the literature on this topic in
Japanese, see Hiroyuki Fukushima, "Nichibei dōmei no rekishiteki suii to rironteki kōzu:
Pawā to kyōi no kinkō to Nihon no dōmei seisaku" [Historical transition and theoreticalframeworks of the U.S.-Japan Alliance: Balance of power and threat theory and Japan's
alliance policy] Kokusai Seiji (International Relations), no. 206 (March 2022): 67-83;
Mayumi Itayama, Nichibei dōmei ni okeru kyōdō bōei taisei no keisei: Jōyaku teiketsu kara
"Nichibei bōei kyōryoku no tame no shishin" sakutei made [Formation of the bilateral defense
system in the Japan-U.S. Alliance: From the conclusion of the treaty to the formulation of the"Guidelines for Japan-U.S. Defense Cooperation"] (Kyōto: Mineruva shobō, 2020); Yoshihisa
Hara, Sengo Nihon o toinaosu: Nichibei hitaishō no dainamizumu [Re-questioning postwar
Japan: The dynamism of Japan-U.S. asymmetry] (Tōkyō: Chikuma shobō, 2020); Jongsung
Lee, "Nichibei dōmei ni okeru Nihon no jiritsusei ni kansuru kenkyū: Hitaishō dōmeiron ochushin ni" [Research on Japan's autonomy in the Japan-U.S. Alliance: Focusing on
asymmetrical alliance theory], Ph.D. dissertation, Kyushu University, 2018; Fumiaki Kubo,
10

"Nichibei anzen hoshō jōyaku no kenri to gimu ni okeru hitaishōsei no kōsatsu" [Study ofasymmetry in the rights and obligations of the Japan-U.S. Security Treaty], in Kibō nonichibei dōmei: Ajia taiheiyō no kaiyō anzen hoshō [Japan-U.S. Alliance of hope: Maritime
security in the Asia-Pacific], ed. Sekai heiwa kenkyūjo (Tōkyō: Chūō kōron shinsha, 2016);
Nobuhiko Tamaki, "Dōmei gainen saikō: Yure ugoku kokusai jōsei to nichibei dōmei"[Reconsideration of the concept of alliance: Fluctuating international situation and the JapanU.S. Alliance], Kanagawa University Asian Reviews 3 (March 2016): 82-97; Sehee Hwang,"Okinawa henkan to nichibei anzen hoshō kyōgi: Dōmei no hitaishōsei no seijiteki shūsei"[The Okinawa reversion and the U.S.-Japan security dialogue: Revision of the politicalaspects of alliance asymmetry], Kokusai Seiji (International Relations), no. 177 (October2014): 113-126; Sehee Hwang, "1970 nendai no nichibei anzen hoshō kankei: Hitaishōsei noteichaku to nichibei kyōryoku no shinka" [Japan-U.S. security relations in the 1970s:
Establishment of asymmetry and deepening of Japan-U.S. cooperation], Ph.D. dissertation,
Keio University, 2012; and Kazuya Sakamoto, "Nichibei dōmei ni okeru 'mono to hito tonokyōryoku' 'hito to hito tono kyōryoku'" ["Cooperation between goods and people" and"cooperation between people" in the Japan-U.S. Alliance], Gaikō fōramu 18, no. 8 (August2005): 15-21.
6

The following works introduce a conditional factor into the autonomy-security trade-offmodel: Jaewook Chung, "Capability Distribution between Allies, Geographical Proximity andAlliance Duration," Korean Journal of International Studies 18, no. 1 (Apr 2020): 1-31; andGlenn Palmer and J. Sky. David, "Multiple Goals or Deterrence: A Test of Two Models in
Nuclear and Nonnuclear Alliances," Journal of Conflict Resolution 43, no. 6 (December1999): 748-70. These works, however, do not explain recent developments in the Japan-U.S.
Alliance.
7

Itayama, Nichibei dōmei ni okeru kyōdō bōei taisei no keisei; and Lee, "Nichibei dōmei ni
11okeru Nihon no jiritsusei ni kansuru kenkyū."
8Morrow, "Alliances and Asymmetry," 905.

9

Ibid, 914. Nations are categorized into three groups: minor, major, and superpowers.

10

Ibid., 911.

11

Ibid., 905, 912, 914. Morrow defines a nation's security as "its ability to maintain thecurrent resolution of the issues that it wishes to preserve" and a nation's autonomy as "thedegree to which it pursues desired changes in the status quo" or "the freedom to pursue
desired changes in the status quo." Ibid., 908-909, 912.
12

The third objective of the U.S. Government listed in the Vandenberg Resolution of 1948 is:"Association of the United States, by constitutional process, with such regional and othercollective arrangements as are based on continuous and effective self-help and mutual aid,
and as affect its national security." "The Vandenberg Resolution (Senate Resolution 239),""The World and Japan" Database,https://worldjpn.grips.ac.jp/documents/texts/docs/19480611.O1E.html (accessed March 25,2022).
13

Mayumi Itayama refers to the Japan-U.S. Alliance as a "symmetric/asymmetric hybrid

alliance." Itayama, Nichibei dōmei ni okeru kyōdō bōei taisei no keisei, 16.
14

On the text of the Japan-U.S. Security Treaty of 1960, see "Treaty of Mutual Cooperationand Security between Japan and the United States of America," "The World and Japan"
Database, https://worldjpn.grips.ac.jp/documents/texts/docs/19600119.T1E.html (accessed
March 25, 2022).
15

Morrow predicts that an ally with growing military capabilities will demand additional

autonomy from its alliance partner and that an alliance partner will demand further autonomy
from an ally with declining military capabilities. Morrow, "Alliances and Asymmetry," 917.
16

Lee, "Nichibei dōmei ni okeru Nihon no jiritsusei ni kansuru kenkyu," 13.
1217Morrow, "Alliances and Asymmetry," 918.

18

"Report by the Subcommittee for Defense Cooperation, Submitted to and Approved by theJapan-U.S. Security Consultative Committee," "The World and Japan" Database,https://worldjpn.grips.ac.jp/documents/texts/docs/19781127.O1E.html (accessed March 25,2022).
19"The Guidelines for Japan-U.S. Defense Cooperation," "The World and Japan" Database,https://worldjpn.grips.ac.jp/documents/texts/docs/19970923.O1E.html (accessed March 25,2022).
20"Cabinet Decision on Development of Seamless Security Legislation to Ensure Japan's

Survival and Protect its People," "The World and Japan" Database,https://worldjpn.grips.ac.jp/documents/texts/JPSC/20140701.O2E.html (accessed March 25,2022). The cabinet decision states that "Under such recognition and as a result of careful
examination in light of the current security environment, the Government has concluded that
not only when an armed attack against Japan occurs but also when an armed attack against aforeign country that is in a close relationship with Japan occurs and as a result threatens
Japan's survival and poses a clear danger to fundamentally overturn people's right to life,
liberty and pursuit of happiness, and when there is [sic] no other appropriate means available
to repel the attack and ensure Japan's survival and protect its people, use of force to theminimum extent necessary should be interpreted to be permitted under the Constitution as
measures for self-defense in accordance with the basic logic of the Government's view todate."
21"The Guidelines for Japan-U.S. Defense Cooperation," "The World and Japan" Database,https://worldjpn.grips.ac.jp/documents/texts/JPUS/20150427.O1E.html (accessed March 25,2022).
22

Dohee Kim, "Case Analysis of the R.O.K.-U.S. Alliance Burden-Sharing through13

Theoretical Approaches to the Evolution of an Asymmetric Alliance," Korea Observer 51, no.
1 (Spring 2020): 31.
23

On the merits of USFJ for Japan, see Kubo, "Nichibei anzen hoshō jōyaku no kenri to gimu

ni okeru hitaishōsei no kōsatsu," 6-8.
24

Japan Ministry of Defense ed., Defense of Japan 2021, 322,
https://www.mod.go.jp/en/publ/w_paper/wp2021/DOJ2021_EN_Full.pdf(accessed January 20, 2022).

25

Thomas C. Schelling, The Strategy of Conflict (Harvard University Press. 1960).

26

On the application of the autonomy security trade-off model to the ROK-U.S. Alliance, see

Kim, "Case Analysis of the R.O.K.-U.S. Alliance Burden-Sharing"; Hwee-rhak Park, "TheSouth Korea-US Alliance under the North Korean Nuclear Threat: A Reluctant Return to the'Autonomy Security Trade-Off'," Pacific Focus 34, no. 3 (Dec 2019): 447-472; and Minhyoung Park and Kwang Ho Chun, "An Alternative to the Autonomy-Security Trade-off
Model: The Case of the ROK-U.S. Alliance," Korean Journal of Defense Analysis 27, no. 1(Spring 2015): 41-56.

14