Japanese National Security Strategy

Under the leadership of the late Prime Minister Shinzo Abe, Japan introduced its inaugural National Security Strategy (NSS) in 2013.[REF] This strategic framework facilitated the reinvestment in and fortification of Japan’s defense capabilities and strategic partnerships, primarily with the United States but also with other partners, especially in the Association of Southeast Asian Nations (ASEAN). Japan has made this change to address its defense needs proactively in response to the evolving security dynamics in the Indo-Pacific region, specifically the dramatic and excessive military buildup by the People’s Republic of China (PRC).

Japan recognizes that it “is facing the most severe and complex security environment since the end of World War II”[REF] and has been consistent in affirming its commitment to defend itself. The Japanese Self-Defense Force (JSDF) already has impressive military capabilities. Now, however, Tokyo has recognized that Beijing’s belligerence and extensive new capabilities represent a real and growing security concern in their region that will require a substantial increase in Japanese defense spending, investment in higher levels of military technology, and changes in strategic thinking.

What has not changed is that Japan seeks to maintain “Open and Stable Seas” and uphold the peace-oriented policy it established after the Second World War.[REF] Japan, like the United States, is a status quo power seeking to uphold the existing Indo-Pacific framework. Prime Minister Abe first coined and defined the Free and Open Indo-Pacific concept that has been thoroughly embraced by the Trump Administration and U.S. policymakers.[REF]

In 2015, after contentious policy debate, the Abe government released a package of defense policy reforms to codify reinterpretations of collective self-defense. These corrections now allow Japan to provide direct support for U.S. military operations if an attack against the United States were to threaten Japan’s survival. These reforms were both a major step forward in U.S.–Japan defense cooperation, indicating Japan’s serious intent to take a bigger role in regional security,[REF] and a significant adjustment in the Japanese national psyche.

Eight years later, under the leadership of Prime Minister Fumio Kishida, Japan revitalized and released its second National Security Strategy in 2022 as a response to continued significant changes in the regional and global security environment. This revised strategy is dedicated to shaping a security environment that rejects unilateral change in the status quo by force. It relies on collaboration with Japan’s ally, the United States, and other like-minded nations to deter and counteract any PRC attempts at such forceful change. Additionally, if Japan were to be attacked, it explicitly states that the JSDF’s primary responsibility would be to confront and defeat the aggressor.[REF]

Currently, Prime Minister Sanae Takaichi is continuing the process started by Abe and rapidly improving Japanese defense modernization. Takaichi, after winning her election in historic fashion, has endorsed a “new golden age of the Japanese–U.S. alliance” that includes accelerating the goal for Japan to spend 2 percent of gross domestic product (GDP) annually on defense spending and expanding its defense industrial base.[REF] Earlier this year, the Japanese government announced that it had lifted bans on exports of lethal weapons, largely in response to “an increasingly severe security environment.”[REF] These decisions follow Prime Minister Takaichi’s comments suggesting that a Taiwan contingency could pose a “survival-threatening situation” for Japan and provide legal justification for Japan to take military action for its self-defense.[REF] The Takaichi government’s alignment with the current U.S. Administration, which may be unprecedented in U.S.–Japan relations, has created an opportunity for new levels of alliance cooperation and defense integration. Prime Minister Takaichi’s clear-eyed understanding and forward-thinking policy decisions show an accurate understanding of the active threats in the region. She is ensuring that resources are applied to support Japan’s national security interests and remains fully cognizant of and sensitive to regional security developments.

Japan’s military alliance with the U.S. is continually reinforced through military coordination and expanded security cooperation in annual bilateral exercises like Keen Edge, Keen Sword, and Resolute Dragon. As part of Resolute Dragon, United States Army Pacific has deployed advanced military systems like the Typhon mid-range missile system, which has had a visible deterrent effect on the PRC.[REF] In 2026, Japan joined the bilateral U.S.–Philippine Balikatan exercise for the first time, deploying 1,400 infantry and other troops in an impressive show of force and commitment.[REF]

Tokyo has also committed more strongly to maintaining peace and stability within the Taiwan Strait, making clear that if war starts in the region, Japan will not only continue to provide military bases for U.S. forces, but also potentially commit its own military forces to assist in defending Taiwan.[REF] Japan’s National Security Strategy characterizes Taiwan “as an extremely important partner and a precious friend…with whom Japan shares fundamental values, including democracy, and has close economic and personal ties.”[REF] The NSS goes on to state that “[p]eace and stability across the Taiwan Strait is an indispensable element for the security and prosperity of the international community, and Japan will continue to make various efforts based on its position that the cross-strait issues are expected to be resolved peacefully.”[REF]

Japan’s bilateral security cooperation with South Korea has been improving as well.[REF] Japan and South Korea have a long history of mutual distrust stemming from actions before and during World War II. Both countries have made significant efforts to improve relationships and move on from 90-year-old differences. The latest whimsical but culturally significant progress is “drum diplomacy.” In January 2026, Prime Minister Takaichi surprised Republic of Korea President Lee Jae Myung with an impromptu drumming session after two days of government-to-government talks. Everybody in both countries saw the President of South Korea smiling and laughing while sitting in Japan. That the event happened at all is tremendously significant. Takaichi, a drummer in college, remembered from a conversation when she first met Lee Jae Myung that “playing the drums [was] a lifelong dream” for him.[REF] In her hometown, she taught the South Korean President to play drums using music from the world-famous South Korean band BTS and the blockbuster South Korean movie K-Pop Demon Hunters.[REF]

Improved relations between the governments and peoples of Japan and South Korea are extremely welcome from the perspective of the United States and should be applauded in Washington. Japan and South Korea have agreed to resume defense exchanges, regular communication between their vice ministers, and engagements between their militaries.[REF] An additional advantage of Japan’s and South Korea’s strengthening relationship is their growing partnership regarding the shared North Korean threat.[REF] The two governments said in a joint statement that their security agreement “not only serves to deter the threat from North Korea but is indispensable to realizing a free and open Indo-Pacific.”[REF]

Unresolved historical disagreements between South Korea and Japan still exist,[REF] but they are being addressed with appropriate diplomatic civility. The current relationship between the two countries is both influenced by the United States’ desire for increased bilateral and trilateral cooperation and shaped by shared Japanese and South Korean apprehension regarding PRC aggression and North Korean threats.[REF]

Constitutional Restrictions

Despite Japan’s forward-leaning National Security Strategy changes in the past 10 years, the Japanese constitution continues to restrict some employment and deployment of the JSDF. As a result, Tokyo may well decide that it is necessary and logical to reinterpret aspects of its constitution. It is important to remember that the Japanese constitution was adopted in November 1946, soon after the war, and reflected a very different security environment. In the 1950s, the Japanese government interpreted the constitution to allow for a Self-Defense Force, which was to be committed solely to self-defense and not “war.”[REF] In subsequent years, successive Japanese governments have continually reinterpreted the constitution to permit wider ranges of operations.

Japan’s Peace and Security Legislation of 2015 gave Japan the authority to exercise the right of collective self-defense and join in combat operations to defend its ally. It also allows Japan to intercept ballistic missiles that are headed toward Guam or Hawaii, join in anti-air and anti-submarine operations, and sweep or lay mines in the waters surrounding North Korea and the First Island Chain.[REF]

Defense Spending Levels

The 2022 Japanese NSS specified a total necessary cost of 43.5 trillion yen ($276.96 billion) from fiscal year (FY) 2023–FY 2027. Japan has been increasing defense spending incrementally over the years, but Prime Minister Takaichi has now increased it substantially ahead of schedule.

Japan’s 2025 defense budget was well under the 2 percent of GDP threshold that serves as the standard for other U.S. allies and was significantly lower than the defense budgets of allies like Germany and France that are routinely criticized for their levels of defense spending. Japan’s comparatively low defense spending has drawn attention from the Trump Administration, and Under Secretary of War for Policy Elbridge Colby has called for a 3 percent Japanese defense budget.[REF]

Japan is making progress, however. In 2025, Prime Minister Takaichi announced that Japan is further increasing its defense spending and is two years ahead of schedule in meeting the 2 percent goal.[REF] In 2026, Japan has made significant additional progress. Its defense budget is roughly 1.9 percent and fast approaching 2 percent, a substantial increase in a relatively short amount of time and an impressive amount for the world’s fourth-largest economy.[REF] Although America’s smaller allies that spend a much higher percentage of GDP on their militaries deserve praise, Washington policymakers well understand that moderate increases by its larger and wealthier allies like Japan and Germany reflect a far greater contribution to collective deterrence and deserve recognition as such.

Tokyo should be commended for increasing its defense budget substantially and well ahead of schedule. This increased spending will allow Japan to realize its necessary defense capability goals ahead of schedule as well, and it is likely that Japanese policymakers will continue to accelerate defense spending ahead of schedule given the dire security situation in the Indo-Pacific.

Defense Spending Priorities

The Japanese defense budget incorporates the proposed increase in defense spending by prioritizing seven fields of “fundamental reinforcement.”[REF] These include:

• Stand-Off Defense Capabilities. “Stand-off defense capabilities” refers to the ability of military forces—primarily using missiles or rockets—to engage adversaries from a distance that exceeds the effective range of enemy weapons and striking those weapons before they have an opportunity to launch. The JSDF is advancing its stand-off defense capabilities by developing and extending the range of advanced missiles including the upgraded Type-12 surface-to-ship missile, Hyper Velocity Gliding Projectiles, and hypersonic missiles.

  Japan is procuring significant numbers of U.S.-manufactured missiles and will soon begin coproduction of U.S. missiles in Japan. Japan is also focusing on diversifying missile launch platforms by developing systems for submarines and transport aircraft to bolster operational capabilities. The JSDF is improving its information collection and command and control systems through satellite constellations, unmanned aerial vehicles (UAVs), and new infrastructure for missile storage and maintenance[REF] to support effective stand-off defense.

• Integrated Air and Missile Defense Capabilities. Integrated air and missile defense is Japan’s coordinated and comprehensive approach to defending against all types of aerial threats, including aircraft, UAVs, and ballistic and cruise missiles. The JSDF is fostering greater integration of air and missile defense capabilities. Japan is procuring additional and upgrading current ground-based warning and control radars by acquiring a future radar system and upgrading the PATRIOT surface-to-air missile system with a new radar (LTAMDS) and interceptor missiles (PAC-3 MSE) to improve its ability to detect and counter Hypersonic Glide Vehicles (HGVs) and similar threats. The JSDF is also modifying the organization and deployment of its fires units to establish a multilayered air defense system, integrating mid-range missile units, and upgrading base air defenses.

  In addition, the JSDF is enhancing its missile capabilities by upgrading the Type 03 medium-range missile and procuring various interceptor missiles such as the SM-3 Block IIA and SM-6 for naval defense. The Japanese Ministry of Defense (MOD) is acquiring Aegis System Equipped Vessels for the JSDF to use in ballistic missile defense operations and developing non-kinetic countermeasures against small, unmanned aircraft using directed energy weapons. This comprehensive approach includes establishing counterstrike capabilities as a defensive measure under strict conditions, managed through unified command and joint operations with its U.S. ally.[REF]

• Unmanned Defense Capabilities. The JSDF is accelerating acquisition of various unmanned systems to reduce potential human casualties and optimize its existing equipment and personnel structures. These decisions focus on enhancing intelligence, surveillance, and reconnaissance (ISR) capabilities through long-endurance UAVs and shipborne unmanned assets for continuous maritime surveillance. 

  The JSDF also plans to employ UAVs to supply remote units and bases. To counter potential adversarial incursions, the JSDF is procuring utility and attack UAVs capable of identifying and responding swiftly to targets on land and at sea. The JSDF is also developing unmanned surface and underwater vehicles (USVs and UUVs) to aid in achieving maritime superiority, and unmanned ground vehicles (UGVs) will be integrated with UAVs to bolster security at military installations. This strategy also includes enhancing coordination between manned and unmanned aircraft and improving the capability for a single person to manage multiple unmanned systems simultaneously.[REF]

• Cross-Domain Operation Capabilities. The MOD and JSDF are focusing on improving information gathering and communication through space-based assets, cyber capabilities, the electromagnetic spectrum, and ground, maritime, and air operational upgrades in order to enhance cross-domain capabilities, including the operation of stand-off missiles. As the highest priority, the JSDF plans to accelerate the acquisition of equipment and improvements to strengthen the capabilities in the ground, maritime, and air domains. Efforts include consistently upgrading equipment and enhancing operational capabilities to collaborate and work in conjunction with unmanned assets.[REF]

  Japan also plans to establish a satellite constellation for enhanced target detection and tracking while incorporating Japan–U.S. cooperation and leveraging commercial satellite imagery to strengthen satellite communication resilience and enhance Space Domain Awareness. New satellite launches are expected in 2026. Additionally, Japan will focus on international collaboration for better resource sharing and information exchange, particularly in space operations.[REF]

  Japan is enhancing cyber capabilities in coordination with national cyber security policies to secure command, control, and critical systems, especially while under cyberattack conditions. Japan is strengthening capabilities to disrupt cyber threats and enhance the cybersecurity of the defense industry with a particular focus on cyber risk management and threat detection.[REF]

  The JSDF is intensifying its electronic warfare capabilities by improving the detection and identification of electromagnetic waves. This program includes procuring advanced systems for communication and radar jamming and developing standoff and stand-in electronic warfare assets. The JSDF is also enhancing signal detection from naval vessels and fixed-wing patrol aircraft as well as developing vehicle-mounted laser devices to counter small UAVs. These efforts will be monitored and managed by the MOD and in coordination with relevant other ministries to ensure optimal and coordinated use of the spectrum across all JSDF activities.[REF]

• Command and Control and Intelligence-Related Functions. The MOD and JSDF will establish data infrastructure and networks that reflect real-time posture to ensure efficient command and control. That posture is both unified and resilient. Specifically, reinforcing information sharing, upgrading command systems, and strengthening autonomous operational capabilities are priorities. Japan is revitalizing its Defense Information Infrastructure as part of improving these command and control functions.[REF]

  Japan is setting up a comprehensive intelligence system for continuous monitoring of military activities near Japan and its territorial waters. This system is designed to enhance intelligence-gathering capabilities in the human, signal, imagery, and open-source domains by such means as unmanned assets and improved collaboration with U.S. forces. The Japanese Defense Intelligence Headquarters is strengthening its functions, expanding training for analysts, and revitalizing intelligence collection and analysis. The JSDF is cooperating with the United States in developing satellite constellations that will improve target detection and tracking.

  Japan is also enhancing its ability to respond to integrated information warfare threats by strengthening its information collection, analysis, and communication systems. It plans to use Artificial Intelligence–driven functions for real-time monitoring and analysis of open-source information to ensure the authenticity and accuracy of communications and better forecast future security scenarios and challenges.[REF]

• Mobile Deployment Capabilities and Civil Protection. Japan is not moving away from disaster response as it improves its offensive capabilities. The JSDF is procuring a range of transportation assets to ensure swift and reliable transportation of both emergency response capabilities and the combat units that would be needed to counter an invasion of Japanese territory. These additional transportation resources include ships in the form of Logistics Support Vessels (LSVs); Utility Landing Craft (LCUs); and small tactical boats as well as KC-46A refueling aircraft and heavy lift CH-47 and smaller utility (UH-2) helicopters. Additional efforts are being made to reduce transportation needs by stockpiling supplies and enhancing the infrastructure of Japanese airports and seaports. The Japanese government is expanding its use of civilian vessels and aircraft for JSDF maneuvers, which will strengthen civil protection training and reinforce JSDF units to help all agencies respond effectively in civil protection circumstances.[REF]

• Sustainability and Resilience. The Ministry of Defense is encouraging Japanese defense industry companies and leaders to expand ammunition production and storage capabilities.[REF] Specifics include (among others) surface-to-ship guided missiles; interceptor missiles for ballistic missile defense (SM-3 Block IIA); interceptor missiles with upgraded capabilities (PAC-3MSE); long-range ship missiles (SM-6); and Type-03 medium-range surface-to-air guided missiles. The MOD is working to purchase and store the fuel required for the JSDF to achieve its operational intent. This will require building new fuel tanks and renting private fuel tanks to keep up with the capacity demand.[REF]

  The MOD plans to eliminate non–mission capable equipment as an element of maintenance budget oversight and at the same time maximize operationally available equipment by 2027. This will require renovation of aging supply warehouses and better forecasting of supply demands. It also will require the outsourcing of maintenance to optimize resources and the introduction of digital transformation in logistics support. The MOD will expand the use of performance-based logistics contracts to ensure that maintenance outcomes meet JSDF requirements.[REF]

  The JSDF will secure and enhance ammunition storage facilities, improve the resilience of key infrastructure, and implement disaster countermeasures to maintain the fighting posture needed to deter adversaries. Some of these enhanced resilience programs include structurally reinforcing existing protective shelters and ensuring that new construction is built “hardened” to withstand attack. The MOD will focus in the next five years on underground basing and above-ground facility improvements while also strengthening base security.[REF]

Force Posture in the Southwestern Islands

The Japanese southwestern islands possess significant military value not only to Japan, but also to the PRC, which covets them for use as staging points, logistics nodes, and protective barriers as well as for legitimizing illegal maritime and illegitimate territorial claims.[REF] Two sets of Japanese islands—the Ryukyu Islands and Senkaku Islands—represent potential flash points for the PRC in the region.

The Ryukyu Islands, of which Okinawa is the most notable, extend 1,200 km southwest from Japan’s southernmost “large island” of Kyushu toward Taiwan. This island chain creates a natural boundary between the East China Sea and the remainder of the Pacific Ocean.[REF] Okinawa is significant both because it is the largest and most populated of the Ryukyu Islands and because of the 20,000 United States Marines stationed there. These islands form natural choke points through which the People’s Liberation Army Navy (PLAN) must travel to reach the greater expanses of the Pacific Ocean.

In the Ryukyu chain is the Miyako Strait, an international waterway that is 129 nautical miles wide. Some of the PRC’s more assertive actions include loitering a seven-ship naval force in the Miyako Strait and a major naval forced transit exercise conducted by the PLAN inside the strait.[REF] The challenge comes in realizing that the PRC claims the Taiwan Strait, which is 30 percent narrower than the Miyako Strait but still 10 times wider than the internationally accepted limit of territorial waters, as its own and then applies a double standard in deliberately conducting a major ship maneuvering exercise in an international thoroughfare that happens to be flanked by two Japanese islands. The increasing intrusion into Japanese airspace associated with this and other similar PLAN activities is a matter of serious concern to Japan.[REF]

The Senkaku islands are near and north of the Ryukyu chain but not part of it. They are administered by Japan but claimed by both the PRC and Taiwan. Because of this dispute, the PLAN has become more aggressive around the Senkakus.[REF] Some of these aggressive actions are assertions by the PRC diplomatic corps and Ministry of Natural Resources that the infamous “Nine Dash Line” of excessive PRC territorial claims is actually a “Ten Dash Line” with China now “claiming almost the entire South China Sea” (as well as extending into Malaysia’s territorial waters).[REF] Other PRC assertive actions are more militarily focused.

Accordingly and in response to these PRC encroachments, the Japanese government has begun to fortify the Ryukyu Islands by building radar stations, stocking the islands with JSDF equipment, and positioning anti-ship missile batteries.[REF] The westernmost tip of the Ryukyu chain—and consequently closest to the PRC—is Yonaguni Island, which would be a frontline territory in the event of armed conflict between the PRC and Taiwan.[REF] The MOD has stationed a coastal observation unit on the island to monitor air and sea traffic near the two archipelagos and into the Bashi Channel between the Philippines and Taiwan.[REF] The island is home to a Japanese Ground Self-Defense Force (JGSDF) training camp that frequently hosts U.S. military forces during bilateral exercises.[REF] Patriot missile batteries are on both Yonaguni Island and the neighboring Ishigaki and Miyako Islands.[REF] The MOD’s planned enhancements include adding another land-to-sea missile unit and expanding the island’s small airport and seaport.[REF]

Mageshima Island is also part of the Ryukyu chain. Japan is constructing a military base on Mageshima that will serve as “an unsinkable aircraft carrier.”[REF] The base will host F-35 fighter aircraft, MV-22 Osprey assault support tilt-rotor aircraft, and air search-and-rescue units.[REF] The planned facilities include two runways, an ammunition depot, and all the elements of a working military air base including arresting gear for “catching” carrier-based aircraft.[REF] Carrier-based aircraft and pilots require a certain number of simulated carrier landings monthly to retain their qualifications for assignment to aircraft carriers. This training is known as Field Carrier Landing Practice (FCLP) and will be relocated to Mageshima from its current location on Iwo To (also known as Iwo Jima).[REF] JSDF training, including exercising the JSDF’s Amphibious Rapid Deployment Brigade, will also occur on Mageshima.[REF]

The Japanese Navy

At the end of the Second World War, the Imperial Japanese Navy was dismantled wholesale. Its successor is the Japanese Maritime Self-Defense Force (JMSDF).[REF] Today, the JMSDF is large and modern. It is comprised of 50,000 sailors and officers and is the second-largest navy in Asia in terms of tonnage.

The JMSDF has two Izumo-class cruisers, originally designed to carry helicopters but now capable of launching F-35 fighters, giving Japan two de facto light aircraft carriers. The JMSDF also has two helicopter carriers, three amphibious tank landing ships capable of carrying amphibious assault vessels and MV-22 aircraft, two dozen attack submarines, 40 destroyers, and nine frigates along with the necessary support vessels to support fleet activity.[REF] The JMSDF is particularly capable when it comes to minesweeping operations and missile defense, as some destroyers are outfitted with Aegis missile defense systems.[REF]

This medium-sized but highly capable and modern navy is expanding under current Japanese modernization efforts. Japan’s naval modernization is focused on ballistic missile defense, multidomain operations, and interoperability with Tokyo’s U.S. ally.[REF] Japan is also expanding and modernizing its frigates and seeks to field 12 modern frigates beginning in 2027.[REF] In short, the JMSDF is adapting to high-speed, high-volume operations, integrating unmanned systems, and enhancing command, control, and logistics to maintain continuous maritime domain awareness.

Japanese Defense Cooperation

Australia. Japanese–Australian defense cooperation is strong and will likely remain strong for years to come. At the United States–Japan–Australia Trilateral Defense Ministers’ Meeting in May 2024, all parties “reiterated their strong opposition to any attempts by the People’s Republic of China (PRC) to unilaterally change the status quo by force or coercion in the South and East China Seas.”[REF] The parties also “confirmed that Australia and Japan would work closely together, and with the United States” on strike capabilities and that “AUKUS partners are considering cooperation with Japan on AUKUS Pillar II advanced capability projects.”[REF] The 2023 Japan–Australia Reciprocal Access Agreement has enhanced interoperability; Japanese and Australian F-35A aircraft have been reciprocally deployed, and Japan conducted its “first anti-air and anti-ship missile launch in Australia” in 2023.[REF]

Japan, Australia, and the United States have participated in joint exercises, expanded cooperation, and depended on regional partnerships in a coordinated manner.[REF] Most recently, in April 2026, Japan and Australia signed the “Mogami Memorandum,” which finalized “contracts for the acquisition of Australia’s first three general purpose frigates” for delivery in 2029.[REF] “[I]n the early 2030s, the general purpose frigate, the Mogami-class, will be the backbone of continuous naval shipbuilding in Western Australia.”[REF]

India. In March 2024, Japanese Foreign Minister Yoko Kamikawa and Indian External Affairs Minister Subrahmanyam Jaishankar affirmed bilateral ties and shared cooperation as members of the Quadrilateral Security Dialogue (Quad). At a press conference, Kamikawa stated that “Japan especially places importance on its relations with India, which has nurtured its own democracy and history and represents the Global South…. In light of the increasingly severe security environment of today, we confirmed the need for our defense and security cooperation.”[REF] Japan and India have agreed to promote interoperability by exploring or committing to bilateral exercises, joint staff meeting frameworks, information sharing, coast guard cooperation, technological and defense-sector collaboration, and coordination of diplomatic positions in regional forums.[REF]

The 2025 Joint Declaration on Security Cooperation between India and Japan transformed “security ties from symbolic gestures and occasional exercises into a broad-based, structured, and forward-looking framework.”[REF] This new degree of defense alignment and cooperation between Japan and India is grounded in their shared interests, strengthens their national defenses, and is facilitating closer relations between the two countries.

The Philippines. On July 8, 2024, in the shadow of increased PRC aggression and unlawful territorial assertion toward both countries, Japan and the Philippines concluded a “groundbreaking” Japan–Philippines Reciprocal Access Agreement (JPRAA) between their militaries.[REF] The JPRAA establishes a legal framework for troop access and logistics as “the security environment in the region becomes more and more severe.”[REF] This is the first time Japan has concluded a reciprocal access agreement with a Southeast Asian country and demonstrates Japan’s continued interest in expanding defense cooperation with like-minded and capable partners with shared interests. More recently, in January 2026, Japan and the Philippines signed a reciprocal agreement “to facilitate the smooth and prompt provision of supplies and services” between their militaries.[REF]

The Republic of Korea. The advancement of Japan–Republic of Korea–United States trilateral ties is a welcome and needed regional security development. Before the trilateral progress, Japan and Korea’s 2016 General Security of Military Information Agreement, which enables the sharing of classified military intelligence between the two countries, had served as the primary active defense agreement.[REF] The more recent enhanced defense groundwork was laid in August 2023 when leader-level meetings at Camp David resulted in a historic elevation of defense collaboration that includes annual multidomain military exercises and the establishment of a hotline to “share information and coordinate” during crisis response.[REF] The Japan–South Korea bilateral defense relationship also continues to improve with discussions on initiating logistics agreements and resuming combined drills later in 2026.[REF]

The United States. The United States is Japan’s only treaty ally. The U.S.–Japan defense alliance, which originated in 1951 and was modified by the Treaty of Mutual Cooperation Between Japan and the United States of America in 1960,[REF] is one of the world’s strongest bilateral defense alliances. In the past, the alliance has largely been understood as one in which the United States provides defense support and offensive strike capabilities while Japan provides more “backstage” enablers in the form of prepositioning, basing, and logistic support. Japan’s openness to potentially reinterpret its constitution and the growing PRC threat have caused the alliance to become more equalized with Japan taking a larger role in its own defense, deterrence, and counterstrike capability.

Japan hosts the largest forward-deployed U.S. force in the world: Roughly 55,000 military personnel, including a carrier strike group, are permanently stationed in the country.[REF] When the families of those servicemembers are included, more than 180,000 Americans live in Japan pursuant to three-year military orders on any given day. This investment enables the United States to project power into the Taiwan Strait, the East China Sea, the Korean Peninsula, and other locations while sustaining combat operations more than 6,000 miles away from America.

On the U.S. side, Washington is transforming U.S. Forces Japan (USFJ)—what had been General Douglas MacArthur’s staff and the senior American military staff in Japan—into a qualified Joint Task Force (JTF) headquarters.[REF] The JTF designation is important because it defines command authority and relationships and confers operational control of all U.S. forces in Japan. Similarly, Japan is standing up its equivalent first-ever permanent Joint Operations Command for the JSDF,[REF] which will have similar country-wide operational control of the Japanese military.

With its many critical avenues of cooperation, including counterstrike capabilities, missile defense, industrial and technological partnerships, and military exercises, the U.S.–Japan alliance forms the bedrock of U.S. power projection in the Indo-Pacific.[REF] The alliance is foundational to the security strategy of both the United States and Japan, and without it, there is no credible deterrence against the People’s Republic of China.

Policy Recommendations

There are several actions that Japan and the United States can take to capitalize on recent progress in the area of defense and national security, especially in view of the growing threat from the PRC. Specifically, Japan should:

• Continue to expand its defense budget to build a JSDF that is capable of securing Japanese security and prosperity. Prime Minister Takaichi’s increased defense spending is to be applauded, and additional increased Japanese defense spending will likewise be applauded. Japan will likely need to continue its recent trend of regularly increasing defense spending to meet its security needs and help to realize its vision of a free and open Indo-Pacific.
• Expand the JMSDF. Japanese naval capacities are of critical importance to regional security, and Japanese shipbuilding is enhancing the capabilities of Japan, Australia, and the Philippines. Japan should expand its own fleet substantially and increase the number of its light aircraft carriers from two to four.
• Increase its defense production collaboration with the United States. Specifically, Japan should build more coproduced missiles like the AMRAAM (Advanced Medium-Range Air-to-Air Missile) and PAC-3 (Patriot Advanced Capability-3 Missile), and the United States should consider Japan to be at the forefront of potential participants in new precision-guided munitions coproduction and codevelopment deals. This will enable Japan to field larger magazines of deep precision strike missiles and missile defense capabilities.

For its part, the United States should:

• Prioritize Japan for military sales and technology sharing. In recognition of Japan’s critical role, capabilities and capacity, demonstrated dependability, and intent to increase defense spending, the United States should significantly increase the levels of technology sharing and licensed coproduction available for Japan and prioritize Japan for military equipment sales.
• Encourage expansion of the Japanese defense industrial base and regional military sales. Japanese industry can handle much higher orders of military equipment both from Japan’s MOD and from other countries that seek to expand their defensive capabilities in the Indo-Pacific. From the American perspective, sales of Japanese warships and munitions in Southeast Asia, for example, contribute to regional security by helping these countries that traditionally do not purchase significant numbers of American weapons systems to acquire modern equipment from Japan.
• In addition, Japan and the United States should immediately begin to exercise the relationship between United States Forces Japan and the Japanese Self-Defense Force’s Joint Operations Command. The U.S. and Japan should capitalize both on the time they have available and on the existing relationships between the two militaries and conduct tabletop exercises between USFJ and the JOC while waiting for the transfer of appropriate authorities (in USFJ’s case) and staffing (in the JOC’s case), which will enable large-scale exercises.

Conclusion

Prime Minister Sanae Takaichi deserves praise for her courage in leading the efforts to transform the Japanese Self-Defense Force into a fully enabled modern military. Tokyo’s increased defense spending is made necessary by the massive military expansion by Beijing and is rightfully first and foremost being undertaken to defend the security and prosperity of the Japanese people. Japan’s emergence as a more typical military power is welcomed by the United States and will enhance the security of the entire Indo-Pacific region.

Wilson Beaver is Senior Policy Advisor for Defense Budgeting and NATO Policy in the Douglas and Sarah Allison Center for National Security at The Heritage Foundation. Andrew Harding is Policy Analyst for National Security and Indo-Pacific Affairs in the Asian Studies Center at The Heritage Foundation. Robert Peters is Acting Director of the Allison Center. Mike Jernigan is a Visiting Fellow in the Allison Center.