GEOPOLITICAL REPORT – U.S. Air Force Modernizes Fighter Presence in Japan: Strategic Shift Towards F-15EX and F-35 Fighters


In the current era of great power competition, the alliance between the United States and Japan stands as a cornerstone of global peace and stability. This partnership is not only crucial for the survival of the postwar liberal international order but also for the security, freedom, and prosperity of the United States. Japan, as the most powerful frontline state in the geopolitical competition between the defenders of the liberal international order, led by the United States, and the revisionist states challenging that order, led by the People’s Republic of China (PRC), plays an indispensable role in this dynamic.

East Asia, with its enormous population, wealth, volume of trade, and industrial capacity, is the most vital region of the world in the twenty-first century. Should Japan fall or become neutralized in the current struggle, the entire region could come under the regional hegemony of the PRC. This would provide the PRC with a commanding position to dominate the Indo-Pacific region and potentially extend its influence globally. As defense strategist Elbridge Colby argues, “Japan is absolutely critical; without it, the anti-hegemonic coalition would almost certainly fail.” Ensuring Japan’s security, freedom, prosperity, and alignment within the liberal international order is thus critical for the United States’ global strategy.

The military bases spread across the Japanese archipelago are pivotal points of strength along the First Island Chain, controlling crucial air and maritime corridors from Taiwan to Russia. These bases envelop much of the Chinese coastline, the Korean peninsula, and Russia’s southernmost maritime province of Primorsky Krai, including the strategic port of Vladivostok. Without these strongholds held by U.S. and Japanese forces, the Republic of Korea (ROK) would be indefensible, and PRC and Russian naval forces would freely project military power throughout the Western Pacific and beyond. This would pose a grave threat to the U.S. Pacific Territories, Freely Associated States, Hawaii, and even the West Coast of the continental United States. Thus, maintaining effective control and use of these bases by Japanese and U.S. forces acting together is essential for safeguarding mutual security interests.

Given their strategic importance, these bases and associated military operations have evolved to better cope with regional threats and provide a more resilient and robust deterrence capability. However, this evolution has been slow and has not kept pace with the rapidly growing threat. Outdated security bargains, bureaucratic rigidity, coordination issues with local communities, and domestic political challenges in both the United States and Japan have impeded the realization of a fully rationalized and militarily effective basing structure. Significant shortcomings include the lack of hardened and resilient base facilities, inadequate shared use of military facilities, limitations on using civilian ports and airfields for military purposes, and persistent political issues associated with the Okinawa bases.

While all statecraft tools—including diplomacy, information and culture, military power, economic and technology policies—are necessary for formulating and implementing an effective grand strategy, this paper focuses on the military aspect of U.S. strategy, particularly the issues related to military bases in Japan.

The Regional Threat Environment

Challenges from Three Strategic Fronts

Over the past two decades, the Indo-Pacific region has experienced extraordinary geopolitical pressures due to the growing power and aggressiveness of the PRC. Additionally, the Democratic People’s Republic of Korea’s (DPRK) development of ballistic missile and nuclear capabilities poses a severe threat to the United States and its regional allies. Furthermore, Russia has been reasserting itself in the region through increased naval and air activities. The growing security cooperation among all three revisionist states threatens to upend the regional status quo, resulting in what many describe as the most severe threat environment in eighty years.

Political scientist Stephen Walt argues that threat perception is a function of four main factors: aggregate power, geographic proximity, offensive power, and aggressive intentions. Japan currently faces all four factors in abundance. According to the 2022 National Security Strategy of Japan, “Japan’s security environment is as severe and complex as it has ever been since the end of World War II. Historical changes in power balances, particularly in the Indo-Pacific region, are occurring. In the vicinity of Japan, military buildups are rapidly advancing, coupled with mounting pressures by unilaterally changing the status quo by force.”

Retired Japan Ground Self Defense Force (JGSDF) Lieutenant General Koichi Isobe argues that the threat may be even more severe because Japan is “challenged from three strategic fronts.” This is the first time Japan has experienced such a broad threat to its security since the Meiji era (1868-1912). The war in Ukraine has intensified this sense of threat. Professor Narushige Michishita, Executive Vice President of Japan’s National Graduate Institute for Policy Studies (GRIPS), argues that the Ukraine war significantly increased Japan’s threat perception because of the realization that “rational actors can make huge strategic mistakes and great powers can cause tremendous damage through war.” Prime Minister Fumio Kishida has frequently remarked that “Ukraine today may be East Asia tomorrow.”

Japanese citizens also perceive a growing threat. In a recent poll by the Yomiuri Shimbun, 84% of respondents “felt Japan’s national security is under threat.” Not surprisingly, the three countries Japanese perceived as posing the greatest threat were China (91%), Russia (88%), and North Korea (87%). Seventy-one percent favored Japan “strengthening its defense capabilities,” with only 26% opposed. Freelance writer Jio Kamata recently authored an article in the Diplomat entitled, “Is Japan Leaving Pacifism Behind?” He concludes that “the Japanese people are increasingly coming to the realization that they are living in an unsettled region and understand the need to step up their own safety.”

There is broad consensus in both Japan and the United States that the PRC seeks to dominate East Asia. Journalist Richard McGregor describes China’s “bedrock ambition” as one of “maximizing its collective economic, military, and political power so it could match the United States in Asia and eventually supplant it as the region’s dominant nation.” The network of alliances and military bases that have defended the status quo throughout the postwar period stands in the way of this hegemonic ambition. These alliances, and particularly the U.S. overseas bases as a product of those alliances, pose a formidable challenge to the PRC’s regional ambitions. The U.S.-Japan alliance and the military bases in Japan are at the very center of that challenge.

The Missile Threat

The greatest threat to U.S. and Japan Self Defense Force (JSDF) bases in Japan is missile attack. Retired U.S. Marine Lieutenant General Wallace “Chip” Gregson notes that “Japan is well within the weapons engagement zone.” As a 2023 Congressional Research Service (CRS) report shows, all the bases in Japan are within range of the PRC’s short, medium, and intermediate-range ballistic missiles. According to Toshi Yoshihara, a former professor of strategy at the U.S. Naval War College, “Chinese analysts see U.S. dependence on a few locations for power projection as a major vulnerability. Therefore, the Chinese conceive their missile strategy to complicate American use of military bases along the Japanese archipelago.”

The United States’ forward defense strategy along the First Island Chain poses a proximity dilemma for U.S. forces. The CRS report points out that “locating military bases close to likely operational areas reduces the transit time and resources required for U.S. forces to conduct combat operations in those areas.” Yet their “proximity to the areas of a prospective contingency entails proximity to adversary air and missile strike capabilities.”

This vulnerability is doubly dangerous from a geographic perspective because of Japan’s lack of strategic depth. As senior defense analyst and former president of the Center for Strategic and Budgetary Assessments (CSBA) Andrew F. Krepinevich, Jr. argues, alliance forces are “at a severe disadvantage relative to China when it comes to strategic depth. They are not in a position to trade space for time and must be prepared to defend forward.” Simply put, there is nowhere to fall back without ceding control of the First Island Chain. Doing so would effectively neutralize the entire region. With its regional allies effectively neutralized, the United States would then be driven out of the region, allowing the PRC to achieve its grand ambition as the regional hegemon of East Asia.

Deterrence by Denial

Although the regional balance of power has shifted in the PRC’s favor, as the revisionist power, the burden of initiating or escalating any regional conflict rests with the PRC. Conversely, as status quo powers, the United States and Japan need only prevent the start of a regional war. The best strategy to counter the regional threat is deterrence by denial.

Deterrence, according to political scientist John Mearsheimer, is “persuading an opponent not to initiate a specific action because the perceived benefits do not justify the estimated costs and risks.” Political scientist Paul Huth further elaborates: “Deterrence is likely to succeed when the potential attacker believes that the probability of military success is relatively low and that the costs of using military force to achieve its objectives are high.” The PRC, because it is initially focused on narrow goals (such as the subjugation of Taiwan) rather than starting a regional great power war, will most likely pursue a limited aims strategy. According to Mearsheimer, the key to success in pursuing this strategy “is the achievement of strategic surprise.” He argues, “success is predicated on the ability of the attacker both to achieve surprise and to overwhelm the defender’s forces that are at hand before the defender can mobilize his main forces.” If successful, the PRC would achieve a fait accompli. For example, if the PRC seizes control of Taiwan, the burden of escalation would be on the status quo powers to reverse this gain at a cost and risk that they may be unwilling to accept. As part of a focused and sequential strategy, the PRC could then dominate the rest of East Asia piece by piece as the credible deterrence of the anti-hegemonic coalition collapses. This scenario is exactly the one that the system of U.S. overseas bases was intended to prevent.

U.S. forces deployed abroad in allied nations are often referred to as “forward deployed forces.” That is because U.S. strategy throughout the postwar period was to establish a forward defensive perimeter far from the nation’s shores along the rimlands of Eurasia to prevent any great power from achieving regional hegemony there. These forces occupy a forward defense position with sufficient tactical mobility to quickly respond to any threat. They constitute a proactive defense posture to prevent the recurrence of a major war rather than waiting to mobilize and respond once a war has already started. This strategy of forward defense proved effective in large part because the bases themselves were relatively secure from external attack. Unfortunately, this is no longer the case.

Today, these forces must also have the capability of surviving a major attack and still maintain a lethal offensive capability sufficient to contest any armed assault that could upend the status quo. Of even greater importance for deterrence, adversaries must also be convinced that the U.S.-Japan alliance has this capability and is willing to use it. They must perceive the cost of aggression as being too great to bear given the anticipated gains. As Colby argues, “true success for such a denial strategy would be for China to see how things would likely unfold and never risk war in the first place.”

To achieve this degree of survivability, the U.S.-Japan alliance must create a more resilient and robust base structure. The military base structure in Japan must be flexible and adaptable to enable the rapid shifting of forces as needed between geographically dispersed facilities that are capable of multi-platform operations. The forces themselves, both U.S. and JSDF, must be well-trained and interoperable to respond as a coherent and lethal fighting force. Unfortunately, efforts to realize these goals have been hindered by the lingering vestiges of a security bargain that was meant to address a far different strategic environment than that which faces the alliance today.

The U.S.-Japan Security Bargain

The Security Bargain Defined

The legal foundation of the U.S.-Japan security bargain is Articles V and VI of the 1960 Treaty of Mutual Cooperation and Security. Article V guarantees United States protection in case of external attack “in the territories under the administration of Japan” while Article VI grants U.S. forces “the use by its land, air and naval forces of facilities and areas in Japan.” This bargain was the product of the Cold War security environment in East Asia. It served the strategic and economic interests of both nations during that era. The principal interest of the United States was the containment of communism and preventing regional hegemony of the Soviet Union in Asia. Japan, however, regarded domestic economic and political priorities as more important than regional security. Japan’s goals were exemplified by the Yoshida Doctrine, a grand strategy that allowed Japan to focus on domestic economic development and political stability while the United States was given wide latitude to provide for the security of Japan and the greater region in a manner largely of its own choosing.

Throughout the Cold War, the United States constantly urged Japan to rearm and enhance its military capabilities so that it could contribute more to homeland defense. This would in turn allow U.S. forces sufficient latitude to project power abroad. Throughout most of the postwar period, U.S. forces and the JSDF operated under a “Sword and Shield” concept. The JSDF provided immediate defense of Japan and the bases while U.S. forces used those bases as platforms for power projection to maintain regional peace and security consistent with its own strategic interests. Shiela Smith, Senior Fellow for Asia-Pacific Studies at the Council on Foreign Relations, notes that “as the SDF became more capable of shielding Japan, the U.S. military had greater latitude and concentrated its offensive capabilities across the region from bases in Japan and elsewhere.” Gregson and political scientist Jeffrey Hornung point out that “because North Korea (and, by extension, China) had no power projection capabilities beyond their immediate shores, Japan was a sanctuary for the United States forces. Collectively, unchallenged U.S. air and sea control in the region became the foundation for U.S. regional presence. This enabled the United States to project force when, where, and how it wished from its secure bases in Japan.”

Strengths and Weaknesses of the Bargain

The security bargain was extraordinarily successful in maintaining regional peace. The stability provided by this arrangement enabled the longest period of economic growth and prosperity within East Asia in modern history. U.S. forces and the JSDF provided complementary roles, missions, and capabilities outlined in Guidelines for Japan-U.S. Defense Cooperation. The United States and Japan first established these bilateral defense guidelines in 1978 and occasionally revised them to adapt to the changing threat environment and as the capabilities of the JSDF improved.

Throughout this period, however, the JSDF was the junior partner in the relationship. While U.S. forces were trained, organized, and equipped for offensive power projection, the JSDF was trained, organized, and equipped for defensive operations. A deeply ingrained bureaucracy for alliance and defense management set in. Civilian bureaucrats seconded from non-defense ministries kept the JSDF on a tight leash. Meanwhile, the United States remained primarily concerned with maintaining its basing rights for the purpose of regional power projection. There was little sharing of missions or assets. Even though many of the U.S. bases on mainland Japan were joint use with the JSDF, the areas of the bases used by each remained sharply segregated.

Not much has changed since. As the CRS report cited above observes, “Despite considerable geopolitical, technological, and doctrinal change in recent years, much of DOD’s basing posture remains, at least in part, the product of decisions made decades previously.” The report goes on to argue that “this has led to a misalignment between regional defense infrastructure and the demands of the current and future threat environment.” This problem is particularly acute in the realm of base defense. According to a 2015 RAND report authored by Alan J. Vick, “since the end of the Cold War, U.S. dominance in conventional power projection has allowed U.S. air forces to operate from sanctuary, largely free from enemy attack. This led to a reduced emphasis on air base defense measures and the misperception that sanctuary was the normal state of affairs rather than an aberration.” Gregson and Hornung argue that “Japan is no longer the sanctuary for U.S. forces that it once was, and this has been true for several decades.”

Is the Security Bargain Obsolete?

Throughout the Cold War era and in the decades after, the U.S.-Japan security bargain served as a conduit for U.S. power projection. It enabled the United States to maintain a defense perimeter far off its Pacific coastline and project power from afar. Japan provided military bases and a minimal defense posture to defend Japan itself, but it was too weak to complement U.S. power. The United States alone possessed sufficient military power to maintain the regional status quo.

Today, because of the decline in U.S. power relative to revisionist states, notably the PRC, such an arrangement is untenable. Retired Japan Air Self Defense Force (JASDF) Lieutenant General Sadamasa Oue argues that “Japan must complement U.S. security to compensate for this relative decline in power.” Gregson contends that “the past ‘sword and shield’ concept is no longer appropriate. We need detailed, combined contingency planning with the Japanese, and we need an alliance command and control structure that enables us to fight as a combined force in direct defense of Japanese territory.” Professor Hideshi Tokuchi, president of Japan’s Research Institute for Peace and Security (RIPS), argues that “Japan must continue to expand its regional role so that the alliance relationship is more symmetrical, or the security relationship will be unstable.”

In other words, the security bargain struck between the United States and Japan over seventy years ago is now obsolete. The shift in the regional balance of power has made it so. Over the past two decades, it has evolved, and continues to evolve, from a security bargain to a security partnership undergirded by a strong security consensus. U.S. forces and the JSDF must aggregate their military power into a fully interoperable force with sufficient power to deter and deny revisionist states from forcibly changing the status quo. Moreover, this security partnership must be embedded in a new regional security architecture comprised of what the U.S. Indo-Pacific Strategy refers to as “a latticework of strong and mutually reinforcing coalitions.”

This evolution of the security bargain into a security partnership must continue. As Abraham Denmark, former Deputy Assistant Secretary of Defense for East Asia, argues, “sustaining the old order is insufficient; must find a way to evolve that order to reflect geopolitical realities.” He further contends that the United States and its allies must transform this regional order “from one that is primarily based on American power to one in which the United States is the leader of a more distributed, networked force.”

For the U.S.-Japan alliance, the full realization of such a transformation will depend on how well alliance managers can interpret the provisions of the Mutual Security Treaty and Status of Forces Agreement (SOFA), both written when the regional balance was far different, to better align with the strategic realities of today. As defense strategists Toshi Yoshihara and James R. Holmes argue, “Times change. Strategists must change with them or find themselves behind the times and risk coming to grief.”

Toward a More Resilient and Robust Base Structure in Japan

Throughout the postwar period, the United States enjoyed naval and air supremacy over the waters and littoral regions of the Indo-Pacific. The system of U.S. military bases in Japan and other allied nations served as “unsinkable aircraft carriers” from which U.S.

forces projected military power throughout the region. Because U.S. bases in Japan were safe from external attack, the JSDF assumed responsibility for their defense while U.S. forces focused on power projection abroad. This arrangement was the core of the sword and shield concept described above.

Today, the situation has changed considerably. According to Colonel Paul Bartok, U.S. Marine Liaison to the JGSDF:

“During the early 2000s, the III MEF (3rd Marine Expeditionary Force stationed in Japan) was focused outward on regional exercises and the Global War on Terrorism. Back then, the Middle East was the major theater of operations. Because there was not a perception of a major threat to Japan, the Marine Corps focused in other areas. As a result, the people of Japan, and especially Okinawa, probably did not regard the U.S. bases as being there for their own defense, but instead to serve U.S. global security interests. With the changing security situation surrounding Japan and the shift of U.S. defense priorities to the Indo-Pacific, the Marine Corps has increased its efforts to work more closely with the JSDF for the defense of Japan and the First Island Chain area. This shift has resulted in a renewed importance of the bases in Japan.”

Indeed, the defense of Japan is now a major focus of recent U.S.-Japan security cooperation efforts to ensure a more resilient and robust base structure.

These efforts are broadly categorized as:

  • (1) base defense measures to improve resilience and survivability in case of attack;
  • (2) distributed operations and greater dispersal of forces across both U.S. and Japanese bases;
  • (3) shared use of U.S. and JSDF bases;
  • (4) dual use of civilian ports and airfields for military forces.

Base Defense

To cope with the rapidly intensifying missile threat, the United States and Japan must invest in a more resilient base infrastructure so that their bases can withstand a major attack, rapidly recover, and continue to generate lethal combat power. Although there is broad consensus for the need to invest in base defense, it has not yet received sufficient focus as part of an integrated defense strategy. The sole exception is active defense measures, such as integrated air and missile defense (IAMD). Yet passive defense measures, such as hardened structures and postattack recovery, have received much less attention and funding. According to Stacie Pettyjohn, Director of the Defense Program at the Center for a New American Security (CNAS), “passive defenses offer an affordable and effective way to counter a range of threats to U.S. bases and forces, but they lack strong advocates in the services, Congress, and industry and thus tend to be overlooked in favor of active defenses.”

Active defense receives by far the greatest focus from defense planners. From a capability perspective, this is the ideal defensive measure because it intercepts and destroys enemy missiles and aircraft before they can strike friendly targets. Both U.S. forces and the JSDF have a robust IAMD capability. Michishita claims that “Japan is the second most capable nation regarding missile defense.” Indeed, Japan has a multi-layered defense system with an upper tier of Aegis-equipped destroyers complemented by a lower tier of Patriot Advanced Capability-3 (PAC-3) missile interceptors. These systems are integrated and coordinated by the Japan Aerospace Defense Ground Environment (JADGE). U.S. forces also have a robust missile defense capability in theater, but these systems lack sufficient integration with Japanese systems.

Yet given the rapidly growing offensive capabilities of the revisionist powers, particularly the PRC, the alliance’s current IAMD capabilities may not be sufficient to counter a mass coordinated attack. As offensive missile systems become more advanced, the current IAMD capabilities will become even less effective in their ability to intercept and destroy them. Moreover, fielding enough active defense systems to completely neutralize the threat may be cost prohibitive. According to Pettyjohn, “surface-to-air missile defenses are expensive and relatively easy to defeat, and the United States cannot afford to field enough defenses to match China’s offensive arsenal. This places existing active missile defenses on the losing side of the cost-exchange ratio.”

A complementary approach to base defense is to minimize the damage of a missile strike through hardening of mission-critical infrastructure. Vick defines hardening as “efforts to protect vital resources (e.g., aircraft, fuel, personnel, and command posts) from enemy attack by reducing the effective radius of attacking weapons.” For airbases, hardening is particularly important. It may include “protective structures for aircraft, buried and hardened fuel and munitions, underground command posts, and other measures to make airfield infrastructure more resistant to attack.” These efforts “view the air base as a system whose primary purpose is the generation of aircraft sorties.”

Hardening was common during the Cold War to protect front-line bases against Soviet attack. Yet since the end of the Cold War, given the overwhelming dominance of the U.S. military, this practice has fallen out of favor with defense planners as costly and unnecessary. According to Oue, “JASDF constructed hardened aircraft shelters at Chitose, Misawa, and Komatsu air bases to protect F-15s from a potential Soviet attack.” JASDF, however, suspended this program after the Cold War. Oue claims that “a similar program now would be very difficult because of the types of advanced weapons currently in use that can penetrate and destroy these types of structures.” He concludes, “today, air bases cannot be sufficiently hardened to withstand such attacks.” Moreover, as Tokuchi points out, “Japanese bases have a very small land footprint. This limits the ability to disperse and harden facilities.”

Nevertheless, hardening can be selectively employed to protect or mitigate the damage to high-value, critical assets. Indeed, the JSDF has planned for the construction of underground facilities, structural reinforcement, and redundancy of utilities infrastructure to “protect major equipment and command posts.” An interesting idea proposed by Michishita is to employ temporary blast barriers as needed to protect vital assets. Temporary barriers are more practical and potentially more cost-effective than permanent constructed barriers. Moreover, they can be erected much quicker than building hardened structures, which also have the vulnerability of being fixed and therefore more easily targeted. Other efforts focus on utilities infrastructure, such as the electrical grid. Yokota Air Base has recently installed an independent power grid, or “microgrid,” that would enable the entire base to operate in “island mode” in case the main electric power source is taken off-line by missile or cyber-attack. Patrick Rory Tibbals, Director of Japan Programs for the U.S. Air Force Life Cycle Management Center Networking Division, argues that network infrastructure is also a strategic asset that must be protected. The best way to do this is to upgrade the physical topology of base networks to a mesh topology that would provide redundant paths between critical distribution nodes. These networks should also have physically redundant paths for long-haul communications between the bases and regional command centers. Critical facilities, such as data centers and network distribution nodes, should also have full redundancy in electrical power and environmental control systems.

As noted above, however, the hardening of facilities has not yet received the level of attention it deserves. On the U.S. side, this is largely due to how the military is funded. According to Pettyjohn, “the services prefer to fund their priority weapons, and are reticent to spend money on supporting infrastructure” for military bases. This is compounded by the expectation that base infrastructure projects should be funded by the Government of Japan (GOJ) as part of the Japan Facilities Improvement Program (JFIP). Yet JFIP is a long and bureaucratically complex process where many projects compete for limited funds. Military Construction (MILCON) is also notoriously slow to deliver. Moreover, fiscal limitations on spending Operations and Maintenance (O&M) funding for base infrastructure projects significantly restrain the scope of those projects that installation commands can self-fund out of their own budget. Simply put, current bureaucratic processes and budgetary authorities sharply restrict what installation commanders can do to protect their bases to better cope with the current threat environment.

The final measure for base defense is postattack recovery. This was an all too frequent activity during World War II when the U.S. Navy Seabees first gained their well-deserved fame by rapidly repairing heavily damaged airfields. Today, the U.S. Navy Mobile Construction Battalions (NMCB) remain active in practicing runway repair at air bases across the globe. In Japan, the U.S. Marines have two deployable Marine Wing Support Squadrons (MWSS) capable of rapid runway repair, one at Iwakuni Air Base and one at Camp Foster in Okinawa. The U.S. Air Force, however, has none. The closest deployed RED HORSE squadron, and the only one assigned to Pacific Air Forces, is in Guam. If the PRC were to launch an attack, then they would have their hands full there. Although the MWSS does have the capability to deploy to other airfields in Japan, both they and the NMCBs could be overwhelmed if the PRC attacks multiple airfields simultaneously. Moreover, rapid deployment of these units would be dependent on adequate airlift support. The current capacity for rapid repair of airfields is almost certainly inadequate given the offensive missile capabilities of the PRC and the degree of damage that it could inflict on military air bases and civilian airfields across Japan.

Finally, but even more importantly, efforts to defend the bases should not be exclusive to those facilities alone. Otherwise, the alliance is neglecting one of the most essential purposes of its existence, which is to defend Japan itself. Gregson rightly argues that “we need to protect civilian areas too,” not just the bases. “This needs to be about protecting all of Japan.”

Distributed Operations and Dispersal of Forces

Because it is not possible to sufficiently protect the bases from attack, the best option to ensure the survivability of air, naval, and ground forces is to disperse them across multiple facilities. This would significantly complicate the People’s Liberation Army Rocket Force’s (PLARF) attack planning. Instead of concentrating their missile attacks on a relatively few large and consolidated military bases while knowing what military units are stationed there, the PLARF would have to target multiple facilities without knowing what forces are located where and when. The force posture at each location would be constantly changing. Such a situation would create enormous uncertainty about the prospects for success and would therefore go far in deterring any such attack in the first place. As Colby points out, “the more resilient, dispersed, and survivable these facilities are, the harder it is for China to ascertain how those forces and facilities would operate, the more targets it would need to attack and the more forcefully it would need to do so.” Vick argues that “dispersing aircraft across many bases increases the number of airfields that adversary forces must monitor and can greatly complicate their targeting problem.”

Recognizing the need for greater dispersal of forces, the U.S. services have adopted distributed operations as a core warfighting concept. The Air Force’s Agile Combat Employment (ACE), the Navy’s Distributed Maritime Operations (DMO), and the Marine Corps’ Expeditionary Advanced Base Operations (EABO) all share this core concept of greater dispersal of forces to enhance their survivability in case of attack. Distributed operations are especially important for aviation units that have traditionally been dependent on large air bases with complex and expensive support facilities that are highly vulnerable. Currently, JASDF’s combat squadrons are stationed at seven main air bases, six on the mainland and one in Okinawa, while the U.S. military has combat squadrons hosted at four main air bases, two on the mainland and two in Okinawa. Two other U.S. military air bases on the mainland primarily serve command and logistical functions. In total, however, Japan has fifty-one runways that are over 8,000 feet long, which is the U.S. Air Force standard for a fighter-capable airfield. There is, therefore, an extraordinary opportunity to disperse these air forces across a much greater number of airfields within Japan. In most cases, however, the GOJ will need to upgrade these airfields so that the appropriate support facilities are available to enable the deployment of a wide variety of military aircraft.

The U.S. military has regularly deployed aviation units to other military airfields throughout Japan since 2007 as part of Aviation Training Relocation (ATR). This program is a bilateral training initiative to improve interoperability of U.S. forces and the JSDF while also more evenly distributing the aircraft noise burden that was previously concentrated at U.S. air bases. ATR has resulted in improved infrastructure at some JASDF bases, thus establishing an important foundation that can be built upon for greater dispersal of air forces. Additionally, Japan’s adoption of the F-35 may enable cross-service maintenance operations between JASDF, U.S. Air Force, U.S. Marine, and U.S. Navy F-35 squadrons. There are five air bases in Japan that either can or will soon be able to provide full support to this complex aviation platform. The U.S.-Japan alliance must continue to focus on improving the capabilities of airfields in Japan to service the full spectrum of military aircraft in support of distributed operations. Yet funding, and the question of who funds what, will remain a significant challenge in achieving this goal.

One glaring problem in this effort is the Henoko Plan for the relocation of Futenma Air Base. The Futenma Replacement Facility (FRF) on the coast of Camp Schwab in Okinawa will be obsolete before it is finished. In fact, its design already makes it obsolete because its short runways severely limit the types of aircraft that can use the base. It cannot, therefore, support distributed operations, which should be the most crucial factor in the construction or upgrade of any military air facility. Moreover, the extraordinary cost of construction siphons away valuable funding that the GOJ could use to upgrade other more capable airfields, both military and commercial. Finally, when the FRF is completed (if it is ever completed), it will be much too late to affect the regional balance. This plan does, however, have the effect of keeping Futenma open indefinitely, though at enormous political and financial cost.

Such sentiments are widely shared in private among military officials from both the United States and Japan. According to a retired general officer from the JSDF, “Henoko is too expensive and not beneficial for military use. It has been a thorn for the Japanese government. It is a waste of money. We can use that money more effectively, but bureaucrats and political leaders are not willing to reopen the pandora’s box.” In early November 2023, during a private press briefing in Okinawa, a senior U.S. officer commented on several deficiencies in the FRF’s design, specifically the short runways. It was his opinion that, because of these deficiencies, the U.S. military should keep Futenma open even if the FRF is eventually completed.

Yet beyond the controversy over FRF, the ability to expand the scope of distributed operations and enable a greater dispersal of forces is dependent on greater sharing of military bases and dual use of civilian ports and airfields across all of Japan.

Shared Use of Bases

As discussed above, Article VI of the Mutual Security Treaty grants to U.S. forces the use of facilities and areas throughout Japan. A separate executive agreement, Facilities and Areas and the Status of United States Armed Forces in Japan (SOFA), governs their use. Article II of the SOFA describes the specific types of use agreements for furnishment of these facilities and areas to U.S. forces. They are:

  • Exclusive Use under Article II 1(a), which grants U.S. forces full and exclusive use of facilities furnished by the GOJ. This is the type of agreement that governs most U.S. bases.
  • Joint Use under Article II 4(a), which grants Japanese nationals (typically JSDF) joint use of facilities furnished to U.S. forces.
  • Limited Use under Article II 4(b), which grants U.S. forces use of Japanese facilities. Although the original intent of this clause was to grant use of these facilities for “limited periods of time,” in practice many limited use agreements are granted indefinitely.

Although most U.S. bases on mainland Japan are shared with JSDF units through various joint use agreements, almost all U.S. bases in Okinawa are exclusive use. The JSDF has limited facilities in Okinawa. Most of those are in urban areas in and around Naha Air Base. Although the JGSDF does occasionally train with U.S. forces on Camp Hansen in Okinawa, they are not stationed together and do not regularly work together. Because of the lack of shared bases, segregation between U.S. forces and the JSDF is greater in Okinawa than mainland Japan. According to Gregson, “Japanese ground forces on Okinawa feel that they are not allowed to access the training areas there.” As a result, there is a lack of coordination between U.S. forces and the JSDF in the area where the regional threat is most severe.

Lack of shared use is also a problem on the mainland but regarding JSDF rather than U.S. bases. While the JSDF does share several of its bases for scheduled training events, there are no U.S. forces permanently stationed on those bases. U.S. forces are stationed on U.S. bases only. Outside of scheduled training or other precoordinated events, U.S. access is permitted only for emergencies. One senior U.S. officer called this emergency use only restriction a “cop-out.” In contrast, according to the Ministry of Defense, “approximately 29% of the land area and 30 of the 76 facilities and areas” that comprise the U.S. bases in Japan are shared with the JSDF.

Shared use of bases by U.S. and Japanese military forces enhances interoperability and allied force cohesion. Military forces that live, work, and train together are more capable than those that do all these things separately. As Gregson argues, “Science (i.e., advanced weapons and tactics) is not enough, we need the understanding and trust that develops only through living, working, and training together daily, from the top of the chain of command (down to) the lowest level.” Colonel Paula Marshall, Deputy Commander of U.S. Marine Corps Forces Japan, remarks that “expansion of shared use would enable more effective collective self-defense.”

Shared use also has tremendous benefits for relations with the local community. Gregson claims that “if we start combining our forces, that will resolve a lot of issues with local coordination. The JSDF does a great job working with the local community. Japanese troops are stationed at their bases much longer and there are no barriers in culture and communication.” Kazuyuki Nakazato, Director of the Okinawa Prefecture DC Office, agrees. He notes that “Okinawans have more understanding with the JSDF because they are Japanese (no language or cultural barriers).” Indeed, he even claims that “some OPG (Okinawa Prefectural Government) officials think that relocation of JGSDF units from Camp Naha (to U.S. Marine camps in Okinawa) could be an option to discuss as a potential consolidation plan of bases on the island.” Nakazato was quick to point out, however, that this does not necessarily reflect the official position of OPG. GOJ would have to first discuss this with OPG. It seems apparent, however, that there are opportunities to alleviate some of the contestation over military forces in Okinawa by implementing greater shared use of U.S. bases. Regarding mainland Japan, it is worth noting that the two bases that have historically had the best community relations, Iwakuni Air Base and Misawa Air Base, also have a long history of joint use going back to the 1950s. In addition, they are the only U.S. air bases in Japan that share their airfield with a Japanese commercial airport.

The topic of shared use received the most attention from the fourteen persons interviewed for this paper, both American and Japanese. All agreed, for various reasons, that there should be much more shared use of bases than currently exists. Isobe argues that “we need more shared use of camps and bases. This is very important, especially on Okinawa. For local communities, shared use is good. It would help with their understanding.” Oue is more specific in his recommendations: “Yokota and Kadena should be joint use for JASDF operational squadrons. Unfortunately, there has been little progress in realizing joint use, even though the strategic situation has changed so much. We need greater resiliency and a more robust sharing of bases. The more dispersal bases we have, the more resilient we become.”

Yet while the Japanese interviewees tended to focus on JSDF access to U.S. bases in Okinawa, the Americans often commented about U.S. forces access to JSDF bases on the mainland. Tibbals argues that “U.S. forces need more access to JSDF bases. The major U.S. bases on mainland Japan are a great example of shared use where the JSDF already has joint use in place.” U.S. Navy Captain Daniel Fillion, Defense Attaché at the U.S. Embassy in Tokyo, contends that shared use on mainland Japan “seems piecemeal.” He argues that “JSDF bases are not as permissive to U.S. operations as we would like. There are still several JSDF bases with very limited access to U.S. forces.”

Although all the interviewees agreed on the importance of shared use, none of them could explain why this goal has been so elusive. The issue of reciprocity, however, was frequently mentioned. One senior U.S. officer claims that “alliance managers on the U.S. side would like to get something in return for sharing their bases in Okinawa. Reciprocity is key! If the JSDF has access to U.S. bases, then the U.S. forces need access to JSDF bases.” A senior U.S. officer formerly assigned to U.S. Forces Japan disclosed that “we have been fighting something of a rear-guard battle to ensure we maintain exclusive control of enough space to ensure we have what we need in a contingency. We need much greater access to their (JSDF) facilities. Opening the door too widely, and too soon for them (JSDF) to come on our spaces decreases momentum to develop the new spaces” on JSDF facilities.” While concerns for reciprocity are understandable and merited, these remarks also provide an important window into what is likely happening across the negotiating table and why achieving greater shared use has been so elusive.

It seems apparent that despite the openly acknowledged need for greater shared use of military bases, this mutually recognized goal breaks down during negotiations over the specifics. Because there is no overarching bilateral plan with specific milestones and timelines that are driven from above, working-level officials are rudderless as they define their own specific goals as well as the timeline (if any) for achieving them. In a bureaucracy, it is much safer to proceed cautiously by emphasizing process and continuity than it is to go out on a limb and take risks to actually accomplish something. As Gregson points out, “past bureaucratic habits become doctrine, then dogma.” That is why leadership is so crucial. Unless decisions are made about shared use of specific facilities at the ministerial/cabinet level with specific timelines for their achievement, the bureaucracy will continue to do its thing and this paper will remain as relevant ten years from now as it is today.

U.S. forces and the JSDF must pursue greater cooperation in the administration of their bases so that shared use and daily joint operations are the norm rather than the exception. Alliance managers must regard all military bases in Japan as joint alliance assets that are available for use by both U.S. and Japanese forces regardless of who administers those bases.

Dual Use of Civilian Facilities

As a complement to shared use of military facilities, both U.S. forces and the JSDF also need access to Japan’s robust constellation of civilian ports and airfields. During a contingency, these facilities will be essential for evacuation of civilian noncombatants, logistics (both military and humanitarian), and for the dispersal of forces. Colby argues that “any war effort against an opponent as powerful as China would have to use things that are dual use. Commercial airports may not serve primarily as military airfields, but they might need to be called into such service, especially if primary airbases are destroyed.” Oue insists that “there are not enough air bases to disperse air forces throughout Japan. We need to mitigate this by using civilian airports as the solution for dispersal of forces. This will require upgrading these facilities by extending runways, building additional aviation fuel storage facilities, taxiways, and other aviation facilities for military use.”

Japan’s National Security Strategy and National Defense Strategy documents describe the need to create an inter-agency coordinating mechanism to “develop and enhance the functions of public infrastructures such as airports and seaports” for use by the JSDF and Japan Coast Guard (JCG). In November 2023, the GOJ identified fourteen civilian airports and twenty-four ports “for upgrades and utilization by the Self-Defense Forces for training and emergencies.” Twenty-eight of those facilities, including all the airports, are in Okinawa and Kyushu. That same month, the JASDF conducted a military training exercise that simulated an attack on Japan. During that event, the JASDF used a civilian airport (Oita Airport) as part of a military exercise for the first time in its history. In March 2024, the GOJ identified an additional five airports and eleven ports for use by the JSDF and JCG. About half of those were in Okinawa and Kyushu.

Most of those facilities, however, require significant upgrades to their infrastructure to make them suitable for military use. The Asahi Shimbun notes that “many of the islands in Okinawa Prefecture have short runways and shallow ports, hindering the accessibility of fighter jets, destroyers and patrol ships to them.” Current and former U.S. and Japanese defense officials also note that these civilian facilities are not yet suitable for military use. Fillion points out that “large infrastructure projects are required, such as port dredging and runway improvements to improve the weight rating for heavy aircraft.” He adds that “we also need support for prepositioning of matériel.” Isobe argues that “airports in the Sakishima Islands (on the southernmost end of Okinawa Prefecture) are relatively good, but the seaports do not have sufficient capacity.”

Dual use, however, is the one defense initiative that requires the most coordination with local governments. Japan’s Port and Harbor Act (sometimes referred to as the “Port Law”) grants local governments the authority to manage port administration. Use of these facilities by military forces and improvements to their infrastructure requires the consent of local governments who manage the civilian ports and airfields. When these facilities are used by U.S. forces, however, the issue can become even more contentious. Although Article V of the SOFA grants U.S. forces free use of ports and airfields for official purposes, this is an executive-level agreement between the two national governments. This provision of the SOFA is not necessarily binding on local governments. Therefore, the legal prerogatives of local governments in administering these facilities in accordance with Japanese law must be respected when negotiating for their use.

Nevertheless, local governments can be persuaded to allow use of these facilities by military forces if they understand the compelling national security need and local benefits that will result. Economic incentives are particularly attractive to local communities. Upgrades of ports and airfields to improve the capacity for military use creates jobs and other economic benefits by increasing the capacity of these facilities. For example, although the OPG’s official request is that military use of civilian ports and airfields should be for “emergency use only,” Nakazato contends that such a request “is made in principle and there can be exceptions. OPG is concerned about the impact to tourism and local reactions to military use of these civilian facilities. If GOJ improves these facilities in a way that provides a benefit to the local community, then this may be an exception.” Isobe points out that “improvements to these civilian facilities will benefit local people by improving the civilian infrastructure. Furthermore, they will be crucial for evacuation of civilians during a contingency.” The GOJ must convince local citizens and their elected representatives that there is a local interest in supporting dual use. They must make these benefits apparent from both a national security and local economic perspective.

Yet for many local citizens, the possibility of military attack provokes deep concerns. While critics may claim that military use of these civilian facilities will increase the likelihood of enemy attack, Oue counterargues that “adversaries will target any facility that can potentially be used for military purposes, including civilian facilities, at their will.” The history of major wars in the past, and even lesser wars today, makes this fact clear. Transportation and logistics infrastructure of all types, civilian and military, invariably become major targets in war. Oue concludes, “to prevent attack, we must strengthen deterrence to prevent war.”

The debate over dual use clearly demonstrates that, as Japan and the United States implement efforts to bolster their forces and bases to deter a major regional conflict, Japanese public support and effective coordination at the local level will become more important than ever.

Public Support and Local Coordination

Public Opinion and Defense Policy

In any democracy, “a high degree of public support is the foundation of a successful foreign policy,” argue political scientists James A. Nathan and James K. Oliver. They contend that, “in the presence of a full debate on complex issues, (the people) are quite capable of forming and articulating informed judgments about their interests and the national interest.” Unfortunately,

Japan’s government and its politicians have, until recently, been largely ineffective at this task. Keio University professor Yuichi Hosoya observes that “there are few liberal democracies that have failed as badly as Japan in holding rational debates over security policy. There are also very few countries where public understanding of security is as limited as it is in Japan.” This lack of strategic understanding among the Japanese public has long frustrated both U.S. and Japanese defense planners in their efforts to bolster deterrence.

Recently, however, this has been changing. The strategic culture of Japan’s state and society is slowly adapting in response to the increased regional threat. A clear majority of Japanese citizens now support bolstering Japan’s national defense capabilities. Recent reforms in defense policy, defense budgeting, defense exports, and weapons procurement manifest this change. As long-time Japan scholar Michael J. Green points out, “none of these reforms in Japan would have been possible without a transformation in the Japanese public’s view of their own military – which in turn resulted from the exogenous security pressures.” Across Japan, this change in strategic culture is also manifesting itself through a more positive attitude towards the military bases generally. Yet the NIMBY phenomenon remains a powerful force that challenges the implementation of specific base policies. This is why effective local coordination is essential to realizing many of the measures described above.

Local Coordination and Acceptance of Base Policies

Local acceptance of foreign military bases in host nations is one of the most controversial, yet least understood aspects of base politics. Japan, a country that hosts one of the largest concentrations of U.S. forces, is certainly no exception. The process of coordination and gaining acceptance from local communities, who have their own interests and priorities, is often frustrating for alliance managers at the central government level. Hence, there is sometimes a tendency to minimize local controversies as “smaller issues” in comparison to the “big issues” of alliance strategy and high politics. Yet if not effectively managed and tended to, these smaller issues can derail those bigger plans. Indeed, all the measures described above are in some way dependent on effective coordination with the local base hosting communities who are most directly impacted by base policies and plans. This cannot be done without first understanding these issues from their perspective.

When confronted with a change in base policy, local base hosting communities engage in a rational, cost-benefit deliberation about the interests of the community regarding the base. Diverse interests within the community are aggregated through mass political movements, and most significantly, elections of local political elites with the legal power and authority to represent the interests of their community. Acting through their elected officials, local communities tend to cooperate with the base when most of its members perceive that the existence and operation of that base is an overall net benefit to the community despite any inherent burdens. Benefits of the base may include enhanced national security, disaster response, business opportunities, national subsidies, infrastructure projects, base jobs, cultural exchange, and other local public goods. Burdens may include the risk of military attack, excessive land use, pollution, crime, accidents, secrecy, cultural conflicts, and diminished sovereignty. The decision to either contest or cooperate with base policies is determined in part by how well basing agreements and their implementation align with the preferences of the local community. Ultimately, however, it is a function of how local citizens perceive the base as either a net benefit or net burden on their community over time. The perceived balance between benefits and burdens is, therefore, the decisive factor in local acceptance of military bases.

On the U.S. side, there is often a tendency to regard problems of local coordination and acceptance as a GOJ problem, that they are obligated by Article VI of the Mutual Security Treaty to provide bases for U.S. forces. How they meet their obligation is a problem for them to solve and not the United States. While this hands-off approach may be correct from a purely legalistic perspective, it is entirely wrong from a practical one. Local coordination, properly understood, is an issue for all sides to manage, not just the GOJ.

The problems of local coordination in Japan are most clearly manifest in the decades-long controversy over Okinawa bases. It is of course beyond the scope of this paper to discuss this issue in depth. Furthermore, there is already a vast amount of literature on this topic. Yet a few salient points are worth noting.

First, the dialogue between the GOJ and OPG is broken. The U.S. side is caught in between this broken dialogue, though base commanders do what they can to try and manage issues at the local level without causing added controversy. During an interview with officials from the OPG Washington DC Office, it was clear that the GOJ has stopped talking to them unless they absolutely must. Unfortunately, there were no opportunities to interview any GOJ central level officials to get their side of the story, but if one side perceives that there is a problem with communication, then that is good enough evidence to show that it exists.

Second, the OPG has contributed its share to the overall problem by making maximalist demands that cannot be satisfied. For example, its insistence that U.S. forces relocate V-22 Ospreys outside the prefecture is a non-starter. Given the vital importance of the Osprey to the defense of the Southwest Islands, as well as regional disaster relief operations, it would be strategically irresponsible for either the GOJ or U.S. forces to agree to this demand. Yet, because of politically driven and questionable claims of the inherent danger of the Osprey, the OPG has remained firm in its opposition to their continued deployment in Okinawa.

Third, although the OPG has professed its support for the U.S.-Japan alliance and even the continued presence of U.S. bases in Okinawa, unresolved base issues remain a serious political problem for the alliance. These cracks in the alliance provide the PRC with an excellent opportunity to engage in political warfare to further undermine the bilateral relationship. The PRC has sought to exploit these controversies to undermine the legitimacy of the Okinawa bases, the U.S.-Japan alliance, and even Japanese sovereignty over Okinawa itself. The Okinawa base controversy remains the greatest threat to alliance solidarity. Moreover, by complicating the defense measures described above, it undermines the alliance’s overall deterrence strategy.

Yet after many years of seemingly fruitless efforts, actors on both sides appear to have given up on resolving these disputes. For anti-base activists in Okinawa, unresolved issues provide their movement with a continued sense of purpose. They have a clear incentive for disagreement. At the central level, there is perhaps hope that the people of Okinawa will see further resistance as futile, accept things as they are, and give up on any further opposition to base policies. Indeed, there are signs that the anti-base movement is losing steam. Moreover, the younger generation tends to be less opposed to the military burden than their elders. The sentiment of thirty-one-year-old Takaya Katayama is typical: “We don’t particularly support or oppose the bases. In our daily lives, we just take it for granted that they exist.”

Nevertheless, simply hoping that the problem will go away through popular ambivalence is a precarious proposition. Public sentiment can rapidly shift because of a catalytic incident. Such an incident can in turn lead to a dramatic resurgence in mass protest over long-held but otherwise dormant grievances. Indeed, the long history of Okinawa base politics provides rich empirical evidence of this phenomenon, of which the 1995 gang rape of a twelve-year-old schoolgirl remains the most infamous and consequential. As in the past, well-established anti-base organizations supported by a sympathetic media would be all too eager to exploit such a crisis to further enflame tensions. In other words, Okinawa may be just one heinous crime or major accident away from popular upheaval, the effects of which upon the bases in Okinawa, and indeed the alliance itself, are unpredictable. To simply wish it all away, then, is a high-stakes gamble that will eventually result in policy failure.

So, given the challenges and given the stakes involved, what are alliance managers to do about the problems of local coordination in both Okinawa and mainland Japan in general?

First, the GOJ and OPG must restore their dialogue. They must repair their relationship and regain each other’s trust. This situation is due in large part to the controversy over the Henoko Plan for Futenma relocation. Nakazato argues that “the Henoko Plan makes it difficult to discuss other matters related to bases in Okinawa.” Therefore, instead of focusing on larger and more contentious issues, such as the Henoko Plan, they should first seek resolution of less contentious issues. Successful resolution of these smaller issues would serve as confidence-building measures to generate greater trust in the relationship. Small wins in the near term can generate a level of trust that enables bigger wins in the future. An incremental approach is therefore the path most feasible.

Second, local governments at both the prefectural and municipal levels should be consulted as early as possible when negotiating new base policies and adjustments to force posture that impact their communities. Both sides must understand what is within the zone of possible agreement and focus on what is achievable rather than standing firm on maximalist demands that the other side cannot accept. But regardless, local governments must be included as part of the process from the outset. Otherwise, feeling left out and ignored, they may become veto players or spoilers that will act to derail implementation of any agreement that lacks their prior consultation or consent. Fundamentally, local communities must be convinced as to how the new base policy or adjustment in force posture will benefit them rather than simply accepting a burden on behalf of the rest of the country. Consulting with local community leaders early in the process to find creative ways to incorporate local preferences into the agreement is the best way to make that happen.

Finally, but perhaps most importantly, while alliance management happens most visibly between high-ranking officials at the central level, it happens more frequently and with vastly more people at the local level. This is especially important for foreign military forces stationed in an allied country. To most Japanese citizens, American military service members, civilians, and their families are the “face” of America and its alliance commitment to Japan. Literally thousands of unseen and unreported daily interactions between base personnel and local Japanese citizens undergird this relationship. For most Japanese who live in a base community, these personal interactions and their experiences of living with the base are what have the greatest impact on their perceptions of the alliance. For them, it is much more than just a military relationship, but also an economic, cultural, and sometimes even a familial one. For base commanders, therefore, the bases must be more than just platforms to project military power. Community relations must be more than just a means to sustain the base presence. It must be about the relationship itself and the people within it. For if the relationship is not managed well at the local level, or if it is not managed at all, then there is little that can be done at the central level to overcome this deficiency.

Today, the Indo-Pacific is the region of greatest geostrategic importance for U.S. grand strategy. The U.S.-Japan alliance is the “cornerstone of peace, prosperity, and freedom” of that region. Yet Japan remains in a vulnerable geographic location as a frontline state where the regional balance of power tilts heavily in the PRC’s favor. Indeed, this sense of strategic vulnerability has been, and remains, a central driver of Japanese grand strategy. Because the distribution of military power would put Japan at a relative disadvantage if it were to balance alone, it must continue to ally itself with the United States, its only formal treaty ally, and also with other like-minded partners to defend the regional status quo. For the United States, the U.S.-Japan alliance is absolutely essential for its regional strategy. Both allies understand that the regional threat is more severe than at any time since the last great power war eighty years ago.

Yet the postwar security bargain between the United States and Japan can no longer effectively deter the regional threat. It is now obsolete. The United States and Japan must instead forge an equal security partnership by abandoning all remaining vestiges of the asymmetrical security relationship. The military bases in Japan – the fortresses of regional stability – must be robust, resilient, and capable platforms for power projection to deter the regional threat, or to defend against that threat if war comes.

The consolidation of U.S. forces on large military bases has created alluring targets for an initial knockout blow. This greatly diminishes their deterrent effect. As the ideal, all bases in Japan should be shared use between U.S. forces and the JSDF for greater dispersal of those forces and to create a more cohesive fighting coalition. This will greatly enhance the alliance’s deterrent effect. Furthermore, the GOJ must upgrade the infrastructure of civilian ports and airfields throughout Japan to support military use on a regular basis, not just in case of a contingency. This will enable greater dispersion of forces and further enhance deterrence. Finally, these measures cannot be accomplished without effective local coordination and enhancing those local relationships that are so vital for both a sustainable basing presence and person-to-person bilateral relations between our two nations.

The purpose of all these measures is to create what former Secretary of Defense Ash Carter describes as a “more geographically distributed, operationally resilient, and politically sustainable” force posture. Indeed, a force posture that is better adapted to the regional threat environment will be more effective in preventing a major war by posing unacceptable costs and risks to revisionist actors seeking to change the status quo by force. The overarching goal is to achieve deterrence by denial in defense of the regional status quo. The U.S.-Japan alliance must make the necessary investments and take the necessary actions described above to achieve that goal.

U.S. Air Force Modernizes Fighter Presence in Japan: Strategic Shift Towards F-15EX and F-35 Fighters

The U.S. Air Force is set to implement significant upgrades to its fighter presence in Japan, marking a pivotal shift in its strategic military posture in the Indo-Pacific region. This transformation involves the deployment of advanced F-15EX fighters to Kadena Air Base and F-35 fighters to Misawa Air Base, reflecting a broader effort to modernize and enhance tactical capabilities amid rising tensions with China.


The Air Force’s announcement, made on July 3, 2024, follows a prolonged period of strategic deliberations. More than a year and a half after plans were first unveiled to repatriate the aging fleet of 48 F-15C/D Eagles from Kadena Air Base, the Pentagon has now detailed the permanent replacements. This decision, made in close coordination with the Japanese government, underscores the U.S. commitment to maintaining a robust and modernized defense posture in the region.

Strategic Significance

The deployment of F-15EX and F-35 fighters is part of a comprehensive $10 billion investment aimed at bolstering U.S. military capabilities in Japan. This initiative aligns with broader U.S. military preparations for potential high-end conflicts in the Pacific, particularly in response to the growing threat posed by China’s military expansion and aggressive maneuvers in the region.

Upgrading Kadena Air Base

F-15EX Deployment

Kadena Air Base, located on Okinawa, will see the introduction of 36 F-15EX aircraft, replacing the 48 F-15C/D fighters. This transition, while reducing the number of aircraft, significantly enhances the base’s combat capabilities. The F-15EX, or Eagle II, is equipped with state-of-the-art systems, including:

  • AN/APG-82 active electronically scanned array (AESA) radar
  • Eagle Passive/Active Warning Survivability System (EPAWSS) electronic warfare suite
  • Advanced fly-by-wire system
  • General Electric F110-GE-129 engines, providing superior thrust and performance

These features make the F-15EX a formidable asset, capable of performing both air-to-air and air-to-ground missions with unparalleled efficiency.

Operational Enhancements

The introduction of the F-15EX at Kadena also marks the first operational deployment of this advanced fighter by an active-duty unit. The Air National Guard will primarily operate the rest of the fleet within the continental United States, highlighting the strategic importance of Kadena in the U.S. defense framework.

Enhancing Misawa Air Base

Transition to F-35A Fighters

Misawa Air Base, currently hosting 36 F-16CM Vipers, will upgrade its fleet to 48 F-35A Joint Strike Fighters. This transition significantly boosts the tactical aircraft capacity and capabilities at Misawa, positioning it as a critical hub for advanced air operations in the region.

Mission Capability

The F-35A, renowned for its stealth and electronic warfare capabilities, will likely assume the Suppression/Destruction of Enemy Air Defenses (SEAD/DEAD) mission currently handled by the F-16CMs. The aircraft’s advanced radar-evading design, coupled with its integrated electronic support measures (ESM) and electronic warfare (EW) suites, makes it exceptionally well-suited for these roles.

Advanced Armaments

The F-35A will also be equipped with cutting-edge weaponry, including the AGM-88G Advanced Anti-Radiation Guided Missile-Extended Range (AARGM-ER) and the Stand-In Attack Weapon (SiAW). These munitions, designed for internal carriage to maintain stealth, enhance the F-35A’s lethality in both air-to-ground and SEAD/DEAD operations.

Marine Corps Adjustments at Iwakuni

The U.S. Marine Corps will also modify its F-35B presence at Marine Corps Air Station (MCAS) Iwakuni to align with its evolving force design modernization strategy. The F-35B’s short takeoff and vertical landing (STOVL) capabilities are integral to the Marine Corps’ distributed and expeditionary operations, particularly in the context of island-hopping scenarios envisioned for Pacific conflict scenarios.

Broader Implications and Future Prospects

Strategic Rebalancing

This comprehensive upgrade of U.S. airpower in Japan is a critical component of the Pentagon’s strategy to counter potential Chinese aggression. The proximity of Kadena Air Base to Taiwan and other flashpoints in the South China Sea ensures rapid deployment capabilities, making it a linchpin in regional defense strategies.

Enhanced Capabilities

The F-15EX and F-35 deployments not only enhance immediate combat readiness but also future-proof U.S. air operations in the region. The F-15EX’s ability to serve as an airborne controller for drones and its potential to carry hypersonic weapons underscore its versatility and strategic value.

Interoperability with Japanese Forces

The deployment of F-35As at Misawa, alongside Japan’s own F-35 fleet, fosters greater interoperability between U.S. and Japanese forces. This synergy is crucial for coordinated defense efforts, particularly in scenarios involving joint operations against shared threats.

Technological Advancements

Both the F-15EX and F-35A represent the pinnacle of current fighter technology, incorporating advanced sensors, communications, and weapons systems. Their deployment ensures that U.S. forces in Japan remain at the cutting edge of military aviation technology, capable of responding to evolving threats with unmatched precision and power.

The U.S. Air Force’s decision to deploy F-15EX and F-35 fighters to Japan marks a significant step in modernizing its military presence in the Indo-Pacific. This strategic shift enhances the capabilities and readiness of U.S. forces, ensuring they are well-prepared to address current and future challenges in the region. As geopolitical tensions continue to rise, these advancements underscore the United States’ commitment to maintaining a robust defense posture and supporting its allies in the pursuit of regional stability and security.

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