Japan’s record defence budget request is really about AI
Japan is moving from a defence buildup centered on adding hardware capacity to a defence transformation centered on integration with intangible force multipliers. This buildup comes with a record defence budget: Japan’s Ministry of Defense (JMOD) requested around 8.9 trillion yen (A$79 billion) for fiscal year 2027. This headline figure does not include a number of strategically important programs left as unpriced ‘item requests’ to be settled during the budget process.
Strategic review in a rapidly changing security environment
Japan’s defence spending has risen rapidly since December 2022, when the government adopted the National Security Strategy, National Defense Strategy, and Defense Buildup Program. This decision to pursue a significant defence buildup was a response to a security environment that had deteriorated and become more complex.
China continues to expand its nuclear, missile, naval and air capabilities while increasing military activity around Japan and Taiwan. North Korea is improving both the quantity and sophistication of its nuclear and missile forces. Russia’s invasion of Ukraine demonstrated the continued willingness of a major power to use force to change the status quo, while Moscow has deepened military cooperation with both Beijing and Pyongyang.
A budget request amid strategic review
The record budget request is JMOD’s response to a deteriorating strategic environment, but it remains a ministerial request rather than Japan’s final 2027 financial year defence budget. Under Japan’s budget process, ministries submit their requests to the Ministry of Finance in the summer. The Ministry of Finance scrutinises the requests and negotiates with individual ministries over autumn. The Cabinet then finalises the government’s draft budget toward the end of the calendar year and submits it to the Diet – Japan’s parliament. The Diet usually deliberates on the budget by the end of March before the next fiscal year begins on 1 April.
From the perspective of the defence budget cycle, FY2027 is somewhat unusual because the budget process is unfolding simultaneously with the revision of Japan’s three principal strategic documents: the National Security Strategy, National Defense Strategy and Defense Buildup Program. The purpose of the revision is to set strategic direction and priorities for resource allocation in today’s unpredictable security environment. Among these documents, the new Defense Buildup Program will set out the capability development and spending framework for FY2027 through FY2031. Consequently, programs whose scope depends on the strategic review and forthcoming strategic documents have been submitted as ‘item requests’ without specified amounts. The roughly 9 trillion yen request covers requirements that can be determined under the current plan, while other programs will be decided during the budget formulation process.
AI moves towards the centre of operations
The most striking feature of the FY2027 request is its emphasis on what JMOD calls ‘new ways of warfare’. Among the nine priority areas identified in the request, the first six are AI, unmanned systems, stand-off capabilities, integrated air and missile defence, space and cyber.
What is particularly significant, however, is not simply that AI appears high on the list. It is that AI is increasingly being treated as the connective element linking many of these capabilities together. JMOD is proposing an operational decision-support system for Japan’s Joint Operations Command, a next-generation ‘AI orchestrator’ platform, highly classified sovereign cloud infrastructure and faster and more resilient information and communications networks. Taken together, these programs point toward a broader objective. They aim to create an operational environment in which large volumes of information from multiple sensors and domains can be collected, integrated, analyzed and presented rapidly enough to support commanders, allowing them to make better and faster decisions.
In this sense, the role of AI goes well beyond administrative efficiency or the introduction of generative AI into routine defence work. The more important function is operational. AI is expected to help transform raw data into usable military information, improve situational awareness, support target identification and selection and shorten the time between detection, decision and action.
This represents an important evolution in Japan’s approach to defence modernisation. Traditionally, modernisation has been understood primarily in terms of acquiring more capable individual platforms – a fighter, destroyer, submarine, radar or missile. But in modern warfare, the effectiveness of those platforms increasingly depends on how well they are connected.
The critical advantage may therefore come from the ability to combine information from many sensors, process it quickly, distribute it securely and connect the resulting decision to the most appropriate weapon.
Seen in this way, AI is not simply another capability alongside space, cyber or stand-off weapons. It is becoming an important part of the architecture that allows those capabilities to function together. This is particularly clear in Japan’s evolving approach to space.
Space becomes part of operational architecture
In July 2025, JMOD released the Space Domain Defense Guidelines, which provide an important conceptual framework for the defence use of space. Space is no longer viewed as only a supporting function for operations on land, at sea or in the air: Japan increasingly regards space as an operational domain. The guidelines call for stronger Space Domain Awareness, more resilient satellite communications, and space-based support for operations in other domains.
They also explicitly connect space capabilities with long-range strike capabilities. To make long-range weapons effective, Japan needs to detect and track mobile targets continuously. The guidelines therefore envisage using satellite constellations, high-capacity communications and onboard AI processing to identify and transmit target information rapidly.
The FY2027 request begins to translate this vision into concrete equipment spending. It includes a space domain awareness satellite, next-generation defence communications satellites, technologies to detect and track hypersonic glide vehicles from space and measures to protect Japanese satellites. It also includes technology enabling AI to process information onboard satellites and communicate with stand-off missiles and other systems. This element is particularly significant, as it illustrates how space is becoming part of the operational chain connecting sensors, data processing, communications, commanders and weapons.
Stand-off weapons are only as good as their targeting system
Japan’s acquisition of long-range stand-off weapons has received considerable international attention since 2022. That effort continues in the FY2027 request. Japan plans further acquisition and development of domestically produced stand-off missiles, new lower-cost long-range weapons and other more advanced systems, including an underwater-launched hypersonic cruise missile.
But the missile itself is only part of the capability. The important part is not simply the missile. It is the entire sensor-to-shooter architecture. Long-range weapons have little operational value without the ability to detect, identify, track and continuously update targeting information on mobile targets over very long distances.
In this vein, one of the most important elements of the budget request is the continued strengthening of targeting capabilities. This is precisely where AI, space, communications networks, unmanned systems and stand-off weapons begin to converge. Sensors find the target. Space systems and other platforms track it. AI processes and fuses information. Networks distribute the resulting operational picture. Command-and-control systems support decisions. Stand-off weapons deliver kinetic effects.
Cyber moves beyond network protection
A similar change is occurring in cyberspace. Japan traditionally approached military cyber primarily as a matter of defending its military networks. That requirement remains essential, but Japan’s approach is expanding.
Under its new active cyber defence framework, Japan is developing capabilities to detect hostile cyber activity earlier and, under defined circumstances, conduct access and neutralisation measures against systems involved in cyberattacks. The FY2027 request also emphasises actively searching for hackers before they cause damage and stronger network resilience.
Cyber therefore increasingly becomes part of military operations rather than simply an information-security function. This is particularly important because integration creates dependency. An AI-enabled force connecting satellites, sensors, commanders and long-range weapons through digital networks can operate much more effectively – but only if those networks remain available under attack.
The real story is AI-driven integration
The most important mistake in reading the FY2027 request would therefore be to treat AI, space, cyber, and stand-off capabilities as separate modernisation programs. The intellectual foundation for integrating them was already visible in the Next-Generation Information and Communication Strategy, released by JMOD in July 2025. The strategy seeks to move beyond systems historically built separately by each institution to establish a common defence information architecture composed of four layers: a sensor-shooter layer, a network-infrastructure layer, a data layer and a service layer.
Seen through this framework, the FY2027 request becomes much more coherent. Satellites, unmanned systems and stand-off weapons populate the sensor-shooter layer. Satellite communications and resilient networks strengthen the network-infrastructure layer. AI, cloud computing, edge processing and data integration reinforce the data layer. The Joint Operations Command’s decision-support system and other operational applications strengthen the service layer. Cybersecurity cuts across the entire architecture.
The strategy also points toward a cross-domain ‘effect web’ in which sensors and weapons can be connected dynamically rather than through fixed, platform-specific kill chains. That is the deeper significance of the FY2027 request. Japan is not simply buying more missiles, satellites, AI systems or cyber capabilities. It is beginning to build the architecture that enables them to operate as one system.
This highlights an important distinction between the defence buildup launched in 2022 and the transformation now emerging. The first phase was primarily about capacity. Japan urgently needed more ammunition, more long-range weapons, stronger integrated air and missile defence, greater resilience and more unmanned capabilities. Those requirements remain. But the next phase will increasingly focus on integration.
This also has direct implications for the US–Japan alliance. Future interoperability will depend less on whether Japan and the United States operate identical platforms than on whether their sensors, data, command-and-control systems and weapons. can exchange information securely and at operational speed. Both the information and communications strategy and the space guidelines explicitly emphasise interoperability with allies and partners. Integration inside the Japan Self-Defense Force is therefore inseparable from integration across the alliance.
The transformation of the Japan Self-Defense Forces
The defence buildup launched in 2022 was, by necessity, primarily about capacity. Japan needed more ammunition, more stand-off weapons, stronger air and missile defences, greater resilience and more unmanned capabilities. That work is unfinished.
But the next phase will increasingly be about converting capacity into combat power. The central question for the next Defense Buildup Program is whether the Self-Defence Forces can overcome technical and institutional barriers and connect sensors, data, networks, commanders and weapons into a resilient, joint, AI-enabled multi-domain force.
The FY2027 request is not the final answer. Much will depend on the revised National Security Strategy, National Defense Strategy, and Defense Buildup Program expected later this year. But the direction is becoming clear.
Japan’s next defence transformation will be measured not only by how much it spends or how many weapons it acquires, but by whether it can integrate those capabilities into a coherent operational architecture. Spending buys capacity. Integration turns that capacity into deterrence.
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