The Role of Japan Maritime Self-Defense Force and U.S.-Japan Alliance in Deterring Chinese Gray Zone Strategy

海上自衛隊佐世保史料館・チョ・ミン・ソウル大学

Introduction

China and its neighbor states are involved in multiple maritime disputes in both the East and South China Sea (ECS, SCS). These disputes range from territorial sovereignty to legal rights in different maritime zones. In the ECS, China, Japan, and South Korea have overlapping Exclusive Economic Zone (EEZ) and Air Defense Identification Zone (ADIZ) claims while China and Japan are in a stalemate over Senkaku/Diaoyu Islands. On the other hand, in the SCS, China, Brunei, Indonesia, Malaysia, the Philippines, Taiwan, and Vietnam are involved in territorial disputes over numerous rocks and islands spread across the region. Furthermore, in the SCS, the U.S. Freedom of Navigation Operations, naval operations intended to preserve freedom of the seas, have also been fomenting much protest from China as it claims the operations ‘undermine Chinese sovereignty.’ The U.S. and Japan both see China’s behaviors in ESCS as coercive and threatening to the established rules-based international order.

一部の学者は、このような中国の行動をグレーゾーンの強制と特徴づけている。本稿では、アジア海上安全保障イニシアチブのグレーゾーン戦略に関する報告書を出発点とする。本稿は、報告書のグレーゾーン戦略の定義と特徴から引き出す。まず、報告書の著者は、グレーゾーンの強制を「直接的かつ大規模な武力行使に訴えることなく、安全保障上の目標を達成しようとする、安定した抑止と保証を超えた一連の試み」と定義している（Green, Hicks, Cooper, Schaus and Douglas 2017）。例えば、代理人の使用、秘密裏の軍事作戦、準軍事活動のそれぞれがグレーゾーン活動を構成する。一部の学者は「ハイブリッド戦略」とグレーゾーン戦略を同義語として使用しているが、この定義では、ハイブリッド戦略が「伝統的な核、通常兵器、および/または非通常兵器の区分を横断する軍事戦術」を組み合わせている（Green, Hicks, Cooper, Schaus and Douglas 2017）ため、グレーゾーン戦略はハイブリッド戦略の概念よりも広範かつ包括的であると見なしている。グレーゾーンの強制は、非対称性、曖昧性、漸進性によって特徴づけられる。7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

‘Neither fully war nor fully peace’ is another phrase often used to describe the characteristics of gray zone activities. However, if one considers Clasuwitz’s definition of war that views wars to exists on continuum, it is difficult to define a threshold that separates a war from gray zone conflict (Green, Hicks, Cooper, Schaus and Douglas 2017). Due to this ambiguity, there are varying definitions of gray zone activities. However, despite this difficulty in delineation, most of those varying definitions tend to use ‘conventional war’ as the ceiling. An actor is more likely to employ gray zone strategies under two conditions; when it attempts to alter some element of status quo and when it perceives its opponent as having an advantage at higher levels of escalation. The stability-instability paradox in which the stability at a higher level of conflict incentivizes challenges at a lower level of conflict well explains this tactic; US conventional military dominance encourages competitors to seek more limited changes to the status quo (Green, Hicks, Cooper, Schaus and Douglas 2017).

This paper will discuss the role of Japan Maritime Self-Defense Force (JMSDF) in deterring such gray zone strategies, specifically those employed by China. JMSDF operates as Japan’s navy since the end of World War II and the dissolution of Imperial Japanese Navy. As an island country with the sixth largest EEZ in the world and 90% of its trade dependent on seal lanes of communication (SLOCs), maritime stability is critical to Japan’s security and prosperity. Japan’s National Security Strategy from 2013 and the National Defense Program Guidelines from 2018 define three goals for the force; to defend Japan’s territory and surrounding areas, to secure the safety of maritime traffic, and create desirable security environment (JMSDF 2020).

Due to the increasing tensions in the ESCS and the subsequently mounting pressure, the U.S. has been promoting Japan’s assumption of a bigger security role in the region. In harmony with this, until the recent resignation, Japanese Prime Minister Shinzo Abe and the ruling Liberal Democratic Party (LDP) were eager to find policy options to further this movement. Indeed, Japan has been gradually increasing its role in the SCS, which is not its direct domain, by enhancing its defense cooperation and capability-building activities with various Southeast Asian countries including the Philippines, another U.S. treaty ally.

これらの状況を検討する中で、いくつかの疑問が生じる。地域における中国のゆっくりとした断固たる主張に対抗する上で、海上自衛隊はどのような役割を果たすことができるだろうか？このようなアジアの海洋紛争および米中競争の文脈において、日米同盟にはどのような意味があるだろうか？これらの疑問を探求することは、アジアにおける海洋紛争の将来への示唆を与えるだけでなく、アジアにおける米国の同盟がどのように競争に影響を与えるかについても光を当てるだろう。7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

between the U.S. and China in an era of low-intensity conflict.

Literature Review

Asian maritime disputes and U.S.-Japan alliance In the context of U.S.-Japan alliance, deterring China’s coercive behaviors means incorporating components of general-extended deterrence. In the specific case of U.S.-Japan alliance, reassurance and burden-sharing are important in understanding the Defense Guideline between the two allies; while the former clearly ensures the U.S. commitment to Japanese defense, the latter reveals that both parties want an expanded Japanese security role in maintain the existing global order by sharing greater responsibilities (Satake 2016). Maintaining a united front among the allies and displaying resolve and commitment, all widely understood components of alliance success, are also drawn from the U.S. alliance experiences in the face of SCS disputes as well (Holmes and Yoshihara 2017).

The role of JMSDF in countering Chinese Coercion In examining the role of JMSDF in the ECS, some argue that Japan’s Coast Guard (JCG) and JMSDF must increase their interoperability and integration since the binary system limits coordination between the civilian agency and military agency and further challenges successfully coping with gray zone operations (Pajon 2017). Meanwhile, some call on drastic changes to the self-defense force to adapt to the rapidly changing security environment and emerging multilateral cooperation in the region (Shimodaira 2014). While different authors have different specific policy recommendations for how the JMSDF could transform so as to counter China’s coercive maritime behaviors, many agree that there is room for change to better address the issues.

中国の活動をグレーゾーン作戦として。一部には「ハイブリッド戦略」という用語がより適切であると主張する者もいるが、ほとんどの学者は、中国のESCSにおける強制的な行動を説明する際に「グレーゾーン活動」という用語を使用している（Patalano 2018）。この問題を論じるほとんどの文献では、グレーゾーンの状況は、平時でも戦時でもない状況を表しており、グレーゾーン戦略は、直接的かつ大規模な武力行使に訴えることなく、国が安全保障上の目標を達成しようとする戦略を構成する（Pajon 2017）。ECSにおいて、この地域における中国の戦略の時間と空間の両方の要素はグレーゾーンの定義に合致する。時間的には、中国は台頭するにつれて現状をゆっくりと変えようとしており、空間的には、尖閣/釣魚島周辺の空間での存在感を徐々に増している。どちらも、日本のレッドラインを踏み越えない程度のペースで行われている（Saito 2018）。さらに、南シナ海における中国の行動も、主にグレーゾーン活動のレンズを通して見られている。例としては、中国が準軍事部隊を統合していることが挙げられる。7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

of fishing and merchant vessels, the seizure of Scarborough Shoal after a standoff with the Philippine Navy, and the massive land reclamation and island-building activities. These gray zone activities that tiptoe around the red line are also quite not enough to provide a casus belli, and as a result, the U.S. has been finding itself with limited options to come to the defense of its treaty allies more aggressively. This, in turn, raises questions about the U.S. security commitment to its Asian allies, a potentially powerful trigger that could gradually alter the established regional order and security architecture (Holmes and Yoshihara 2017).

Gap in the literature While it is generally agreed that China’s activities in ESCS could be understood through the lens of gray zone operations, there is some disconnect between the established literature on U.S.-Japan alliance and China’s gray zone strategies. Contextualizing the former in terms of the latter will enable us to further understand how general-extended deterrence and alliances transpire in a world where a full-blown interstate military conflict is becoming increasingly rare but the tensions between great powers are mounting. Furthermore, by focusing on the role of JMSDF, this paper will add to the current discussion on the direction of the U.S.-Japan alliance and security cooperation as well as Japan’s future security role in the region.

Theoretical Framework

This paper will employ the framework of classical bargaining theory’s means of signaling foreign policy interests. Bargaining theory is often referred to as ‘the workhorse’ theory of war and is one of the most widely used approaches for explaining war initiation, escalation, and termination (Lake 2010). Fearon’s costly signals further explain important aspects of the bargaining theory. Two means of signaling an actor’s foreign policy interests are important for this paper. One is tying hands, which is deterrence by punishment. Militarily, formal alliance treaties or trip-wire forces serve this purpose while diplomatically, public statements that create domestic audience cost that will incur ex post if not followed through are an example. On the other hand, sinking costs is deterrence by denial; taking actions that are costly ex ante. For instance, militarily, increased defense spending, troop mobilization, arms buildup, foreign land troop stationing all constitute cost-sinking. Economically, sanctions on target actors and increase in trade ties with allies serve this purpose (Fearon 1997).

さらに、ハスの拡張抑止に関する研究は、日米同盟と本稿の拡張抑止の側面を導くだろう。拡張抑止の信頼性と安定性の測定における2つの変数がここで考慮される。最初の変数は、7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

Protégé state to the Defender state, measured by the existence of a military alliance, Defender to Protégé arms transfer, and level of economic integration. Another is the scale of escalation; the first level, a symbolic show of force or display of military presence (naval visits to ports of protégé, the dispatch of a warship to a coast of protégé, naval reconnaissance off cost of protégé) and the second level, a demonstration of military capabilities (naval exercises or war games held near the coast of the protégé or adversary) will be used (Huth 1991).

Methodology

This paper will employ the qualitative method. It will first collect information relevant to national interest, security strategy, regional strategy and recent military activities from official documents from the respective governments of the U.S. and Japan. These will include defense white papers and strategy report documents. Then, employing deductive reasoning, this paper will examine them through the lens of the previously mentioned theoretical framework, borrowing from bargaining theory, foreign policy interest signaling, and Huth’s work on extended deterrence. The analysis will focus on the role of JMSDF and the U.S.-Japan alliance in deterring Chinese gray zone strategy.

Analysis

China’s Gray Zone Activities in the SECS The U.S. defines China’s campaign of low-level coercion aimed to assert control of disputed spaces as gray zone activities. Such a perception is clear in the quote “China is using a steady progression of small, incremental steps in the “gray zone” between peaceful relations and overt hostilities to secure its aims, while remaining below the threshold of armed conflict.” In this definition, political warfare, disinformation, use of anti-access/area denial (A2/AD) networks, and economic leverage are categorized as gray zone coercion (The Department of Defense 2019).

この戦略を表す具体的な中国の活動は数多く存在する。例えば、南シナ海では、2012年に始まったスカーボロ礁の対立は、比較的小さなフィリピンを圧迫し続ける低レベルの強制である。漁船、輸入禁止、フィリピンへの漁業禁止を利用して、中国は徐々にその領有権の実効支配を推し進めた。現在、中国海警局は、その地域に常に存在している。この事例では、中国は全面的な武力紛争には関与しなかったが、それでも7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

low-level tensions and at the end coerced the Philippines out of Scarborough Shoal (Mazarr 2015).

On the other hand, in the ECS, China’s proclamation of air defense identification zone (ADIZ) and frequent scrambling of its fighter jets exemplify China’s gray zone strategy in the region. Like its actions in the SCS, China’s actions surrounding the contested Senkaku/Diaoyu Islands are also intimidation short of full-scale warfare; China has been not only increasing its naval presence around the feature but has also been employing media fusillades and diplomatic protests as well as economic tools of coercion. For instance, in 2010, when the Japan Coast Guard boats and a Chinese fishing boat collided and JCG took the Chinese crew, China put restrictions on the export of rare earth mineral to Japan (Hornung 2020).

These Chinese activities display all three of the previously mentioned characteristics of gray zone strategy; asymmetric capabilities, ambiguous status between clear aggression and low-intensity conflict, and most of all, incrementalism. Especially in the SCS, China has been “salami slicing its way” to achieving its objectives while cautiously and intentionally avoiding high-intensity conflict or military conflict so as to create a “sufficient balancing dynamic to effectively check its activities” (Mazaar 2015).

U.S. Interests and Strategies The National Security Strategy published by the White House clearly lists China as the biggest threat in the region. The document emphasizes that while the U.S. seeks to cooperate with China, it strongly disagrees with China’s use of economic inducements and penalties, influence operations, and implied military threats aiming to engage in low-level coercion and advance its economic and security interests. As some of the American efforts at countering these gray zone activities, this document emphasizes coordination and cooperation with its regional allies. South Korea, followed by Japan and Australia are mentioned in stating that the U.S. welcomes and supports the strong leadership role of its allies. Additionally, this document sets the assurance of freedom of the seas and “peaceful resolution of territorial and maritime disputes in accordance with international law” as its priority goal (The White House 2017).

一方、米国国務省が発行した「自由で開かれたインド太平洋、共有ビジョンの推進」という文書は、すべての国が「主権において安全であり、国際法と公正競争の原則に沿った経済成長を追求できる」地域における海洋の開放性に対する米国のコミットメントを強調している。この文書は4つの価値を強調している。(1)すべての国の主権と独立の尊重。(2)紛争の平和的解決。(3)開放的な投資に基づく自由で公正かつ相互的な貿易、7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

transparent agreements, and connectivity; and (4) adherence to international law, including freedom of navigation and overflight.

As NSS does, this document also puts a strong emphasis on cooperation collective action with its like-minded allies and partners in managing transnational issues such as piracy and terrorism and protecting the maritime freedom. Japan in specific is mentioned in two ways; one is through the Trilateral Strategic Dialogue, which engages the U.S., Australia, and Japan on “matters in such as sustainable infrastructure development, maritime security, and counterterrorism,” while the other is the Quadrilateral Consultation with Australia, India, and Japan. Additionally, the document’s emphasis of its policy overlap with Japan’s Free and Open Indo-Pacific concept, India’s Act East Policy, Australia’s Indo-Pacific concept, and the ROK’s New Southern Policy, displays the value the U.S. puts on a network of allies and partners (The Department of State 2019).

Finally, Indo-Pacific Strategy Report: Preparedness, Partnerships, and Promoting a Networked Region, published by the U.S. Department of Defense, opens with a message that defines the Indo- Pacific as its priority theater. As the previous document does, this one also highlights “the competition between free and repressive world order visions” as the primary challenge for the U.S. national security. It also specifically points to the PRC and the China Communist Party (CCP) as seeking to “reorder the region to its advantage by leveraging military modernization, influence operations, and predatory economics to coerce other nations.” Furthermore, its detailed mention of China’s pursuit of the previously mentioned A2/AD strategies is noteworthy; the document records that these A2/AD capabilities could be “used to prevent countries from operating in areas near China’s periphery.” In further explaining China’s “use of military presence to exert de facto control over disputed areas,” it specifically touches upon the SCS as well as Senkaku Islands in the ECS. In delineating the security environment, this document specifically uses the term ‘gray zone strategy’ to describe Chinese low-level coercion.

Additionally, this document also emphasizes the U.S. efforts in building a network of partnerships capable of aggression deterrence, stability maintenance and common domains access preservation. Among the various multilateral relationships this document mentions, five includes partnerships between Japan-ROK-U.S., Australia-Japan-U.S., India-Japan-U.S., and the quadrilateral consultations (Quad) between Australia, India, Japan, and the U.S. The document reiterates that the U.S. cannot address the newly emerging challenges alone and it must work with like-minded allies and partners (The Department Defense 2019).

日本の国益と戦略。2016年8月、安倍晋三首相は初めて「自由で開かれたインド太平洋」を発表した。7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

concept, aiming to foster regional stability and prosperity through a free and open Indo-Pacific region. The three pillars of this concept include; (1) promotion and establishment of the rule of law, freedom of navigation, and free trade (2) pursuit of economic prosperity (3) commitment to peace and stability.

The Japanese defense white paper’s section on the Constitution and the Right of Self-Defense as well as the government’s view on Article 9 illustrate the legal changes that prepare Japan to take on a greater military role. With the new legislation in 2014, under the “Three New Conditions,” Japan is permitted to exercise measures of self- defense. The three conditions include: (1) When an armed attack against Japan has occurred, or when an armed attack against a foreign 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 (2) When there is no appropriate means available to repel the attack and ensure Japan’s survival and protect its people; (3) Use of force to the minimum extent necessary (Japan Ministry of Defense 2020).

On the other hand, Japan’s National Defense Program Guidelines published in 2018 clearly identifies gray-zone situations as a critical threat to Japan’s national security. In delineating the threat China poses on Japan, these Guidelines recognize China’s high-level growth of defense expenditures and lack of transparency in its defense policy and military power and China’s unilateral and coercive attempts to alter the status quo as major issues. In expanding upon these points, the document mentions both the ECS and the SCS; it identifies China’s constant violation of Japanese territorial waters around the Senkaku Islands as a major threat to itself and China’s large-scale land reclamation and militarization of the disputed features in the SCS as a threat to the rules-based international order.

In order to face these challenges and protect Japan’s national interests, these guidelines proclaim that the government will strengthen its own architecture for national defense as well as Japan-U.S. Alliance. A key component of the latter worth mentioning here is Japan’s intention on increasing Japanese and U.S. presence in the Indo-Pacific region; the guidelines state that Japan will conduct various bilateral activities including capacity-building assistance, humanitarian assistance/disaster relief and counter-piracy (Japan Ministry of Defense 2019).

日米同盟の国益と戦略。2015年に発行された最新の「日米防衛協力のための指針」は、1997年に発行された前回のバージョンとは大きく異なる。指針では、日本の島嶼への武力攻撃が発生した場合の米軍と自衛隊の役割が初めて明記されている。しかし、7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

U.S. military’s operations during this occasion are limited “to support and supplement the SDF’ operations,” its significance is in the fact that the United States has made a commitment to defend Japanese offshore islands, which encompasses the disputed Senkaku islands (Japan Ministry of Defense 2015).

On the other hand, the joint statement after the security consultative committee meeting in 2019 affirmed the alignment of the two countries’ regional strategic policies. The statement recognizes the common emerging challenges that threaten the rules-based international order and emphasizes cooperation between partners and allies. In particular, the ministers expressed strong opposition to “unilateral coercive attempts” in the ESCS. This 2019 joint statement also reconfirmed the previously mentioned U.S. commitment to the defense of Japanese offshore islands by stating that Article V of the U.S.-Japan Security Treaty applies to the Senkaku Islands. Both sides agreed on the importance of enhancing alliance capabilities and increasing operational readiness and cooperation (Japan Ministry of Defense 2019).

Another noteworthy point in this statement is that the U.S. welcomes Japan’s “proactive steps to strengthen its defensive capabilities, with the Ministers confirming that both nations need to constantly re-evaluate their roles, missions, and capabilities.” The statement also mentioned the two allies’ support for ASEAN centrality and peaceful resolution of conflict in accordance with international law as well as other multilateral cooperation mechanism such as the Trilateral Strategic Dialogue and trilateral joint exercises.

Signaling: Tying Hands and Sinking Cost In signaling their alliance commitment, the U.S. and Japan employ several signals. First, the U.S.-Japan Treaty of Mutual Cooperation and Security and the recent affirmation of the U.S. commitment to defending Senkaku Islands tie hands militarily and diplomatically, respectively. Second, JMSDF’s increase in defense spending and arms buildup as well as the U.S. troops stationed in Japan sink costs. The below figure shows the change in Japan’s military expenditure in the past fifteen years. After the gradual decrease between 2006 and 2012, there has been a steady increase at a higher rate than the initial decrease.

Figure 1 Change in Defense-Related Expenditures (Japan Ministry of

Defense 2021a) 7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

Furthermore, Japan’s buildup of defense capability in fiscal year 2020 shows Japan’s significant investment in its maritime capabilities; the buildup includes but is not limited to the construction of two destroyers, a submarine, and a minesweeping vessel and the partial refurbishment of Destroyer JS IZUMO for takeoff and landing by F-35B (Japan Ministry of Defense 2021a). F-35B, variant of the American F-35 fighter that is capable of short takeoffs and vertical landings are a great fit for JMSDF’s helicopter carriers that resemble an aircraft carries. In 2018, Japan acquired 42 F-35B fighters for carrier duty. Furthermore, in line with the 2018 National Defense Policy Guidelines that presented Japan’s plans to add three more submarines to its 19-boat fleet by 2023, in October 2020, JMSDF launched JS Taigei (Japan Ministry of Defense 2021a). On the other hand, 54,000 military personnel to Japan, in the U.S. Navy’s Seventh Fleet, U.S. Marine Corp’s III Marnie Expeditionary Force, 3 Air Force wings, and smaller U.S. Army and Special Operations units (The Department of Defense 2019).

Some joint naval engagements are worth noting as well. For example, between May 2 and 8, 2019, the first joint sail by U.S., Indian, Japanese, and Philippines navies took place. This four-way naval engagement with six ships sailing through the SCS demonstrated presence and cooperation (Panda 2019). In terms of exercises, among the 60 exercises (1 planned but canceled due to COVID-19) that took place in 2020, nine were in the SCS; (1) Japan-Singapore in June (2) Japan- U.S. in June (3) Japan-U.S. in July (4) Japan-Philippines in July (5) Japan-Australia-U.S. in July (6) Japan-Australia in September (7) Japan- Indonesia in October (8) Japan-U.S. in October (9) Japan-Australia-U.S. in October.1 These broader engagements in regions that do not directly concern Japan’s homeland security illustrate Japan’s plan to assume a larger role in the broader Indo-Pacific region.

The Role of JMSDF However, the gap between the maritime capabilities between the U.S. and Japan is considerable. In considering naval strengths of different countries, the author believes that examining the range of power projection is more important than simply studying the number of assets. Only considering the number of assets does not accurately reflect the actual capabilities. For example, Global Firepower counts that the North Korean Navy possesses 492 assets in total while the U.S. Navy trails this with 490 assets. Meanwhile, the dataset shows that JMSDF’s naval assets totals at 155 (Global Firepower 2021). Hence, to get a more accurate understanding of the actual naval capabilities of the U.S. and Japan, this paper instead studied the Todd and Lindberg classification system that ranks blue-water navies into 4 classes depending on power projection; (1)global-reach power projection 1 “Exercises,” JMSDF, https://www.mod.go.jp/msdf/en/exercises/. 7. The Role of Japan Maritime Self-Defense Force and U.S.-Japan Alliance in Deterring Chinese Gray Zone Strategy_해상자위대 사세보 사료관

(2)limited global-reach power projection (3)multi-regional power projection (4)regional power projection (Todd and Lindberg 1996). According to this classification, the U.S. is the only country that qualifies as having global-reach power projection, capable of carrying out multiple and sustained global power projection missions. On the other hand, Japan is included in the fourth rank as it is has limited range power projection beyond EEZ.

Hence, it is more realistic that in striving to increase Japan’s role in the U.S.-Japan security cooperation, neither country expects JMSDF to rapidly develop its power projection capabilities or increase its number of assets. Likewise, it would be unreasonable to expect Japan to suddenly become a security partner that cooperates with the U.S. on its global missions with a comparable level of contribution. Rather, it is more likely that in attempting to increase Japan’s role in the U.S.-Japan alliance and deterring China’s gray zone activities, both parties envision that Japan will gradually increase its naval capabilities and assets and rise through the ranks. Meanwhile, Japan is starting to play a more active role in the region in which many countries are caught in the U.S.- China competition. Such a Japanese role could considerably lighten the load of the U.S. in the Indo-Pacific region. For instance, as previously examined, Japan’s bilateral and naval exercises and trainings have primarily been with countries in the Indo-Pacific, including India, Australia, the Philippines, and the Singapore. In short, while the U.S. and Japan aim to expand Japan’s role in their security cooperation and deterring China’s gray zone activities, because of the limited naval capabilities of JMSDF, JMSDF’s proactive role is mostly limited to the Indo-Pacific.

Conclusion

米国と日本は両国とも、中国がその存在感を増し、係争地域の実効支配を確立しようとすることで、自国の国益を推進しようとしているグレーゾーンの強制、低強度紛争、エスカレーションについて懸念を表明している。両国は、このような行動がルールに基づいた国際秩序を脅かすものと見なしている。両国は、同盟国間の協力がこれらの課題に対処するために不可欠であると強調している。様々な戦略文書において、米国は同盟国やパートナーとの協力の重要性と、それらの関係を拡張されたネットワークへと発展させることによって強化することの重要性を強調している。日本の公式文書も、同盟とパートナーシップのネットワーク戦略が米国の戦略と一致していることを示している。さらに、自衛隊も変革している。例えば、安全保障指針を改定し、日本が7. 中国のグレーゾーン戦略を抑止する上での海上自衛隊と日米同盟の役割_海上自衛隊佐世保史料館

self-defense.

These strategies are reflected in the costly signal activities that two countries engage in. The alliance treaty between the two countries and the U.S. statement affirming its commitment to defending Japanese offshore islands signal the U.S. commitment by tying hands. On the other hand, the U.S. military personnel stationed its bases in Japan, the U.S. arms sales to Japan, Japan’s own arms buildup and increased defense spending, and various joint exercises sink cost to signal their foreign policy interests. Most notably, these joint military exercises are becoming a ‘network.’ As the U.S. emphasizes that one country cannot address these 21st century challenges on its own, Japan is starting to engage more proactively, especially in the SCS.

米国の、特に大陸本土に囲まれていない海であるESCSにおける中国のグレーゾーンの強制を抑止することは、困難な任務である。拡張抑止のジレンマの論理が示すように、米国がパリやボンを犠牲にしてワシントンD.C.やニューヨークを危険にさらすことは、本質的に信頼性が低い。これは、中国がESCSでグレーゾーン活動に従事している理由の一つである可能性がある。中国は、米国が紛争における大規模なエスカレーションをリスクにさらすほどの十分な関心をこの地域に持っているとは信じていないからである。しかし、日米間のシグナリング活動と、特にASEAN諸国との間で、志を同じくするパートナーのネットワークを形成するために海上自衛隊が行うネットワーキングの努力を通じて、米国と海上自衛隊はESCSにおける中国のグレーゾーン活動を抑止する上で不可欠な役割を果たすことができる。

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