The Japanese Ministry of Defense (MOD) has earmarked 734 billion yen or $5.16 billion in its FY2024 budget for bolstering stand-off defence capabilities. The budget document specifies that these capabilities will be strengthened to address potential threats from naval vessels and landing forces attempting to invade Japan, including its islands. This allocation encompasses various elements, such as the development, acquisition, and expansion of production facilities for domestically produced missiles and guided munitions. Additionally, it includes the procurement of the Joint Strike Missile (JSM) and Joint Air to Surface Standoff Missile (JASSM). Furthermore, the budget covers the expenses associated with enhancing the Japan Maritime Self-Defense Force (JMSDF) ships by adding Tomahawk cruise missile launch capabilities. The budget requests for the maritime domain are outlined as follows-
Construction of two Aegis system-equipped vessels – ASEVs ($2.6 billion)
The Japanese Ministry of Defense has successfully secured $2.6 billion (373.1 billion yen) for the fiscal year 2024. This funding is designated for the construction of two Aegis System Equipped Vessels (ASEV), serving as an alternative to the previously abandoned land-based Aegis Ashore ballistic missile defence (BMD) system. The cancellation of the Aegis Ashore project in June 2020, during the Shinzo Abe administration, was motivated by concerns that falling components from missile interceptors might pose risks to densely populated areas in Japan.
In addition to the $2.6 billion allocated for the ASEV construction, the Ministry of Defense has also secured $572 million (81.5 billion yen) to cover various related expenses. These expenses include test preparations and operational support equipment, such as test sites. Consequently, a total budget of $3.2 billion (454.6 billion yen) has been earmarked specifically for the two Aegis System Equipped Vessels in the fiscal year 2024.
Construction of two new FFMs ($1.2 billion)
The Defense Ministry has announced plans to acquire a total of 12 new FFMs (Fast Frigates Multi-Mission) to succeed the Mogami-class FFM for the Japan Maritime Self-Defense Force (JMSDF). In the upcoming fiscal year, the ministry has allocated $1.2 billion (174 billion yen) in the budget for the construction of the first two vessels, with deployment scheduled for Fiscal Year 2028.
The new-class FFMs are designed to feature advanced capabilities, including longer-range missiles, improved anti-submarine capabilities, and enhanced functionality for various maritime operations. Specifically, the ship-launched, upgraded version of the Type 12 Surface-to-Surface Missile (SSM) and the new Ship-to-Air Guided Missile (A-SAM) will be integrated into the new-class FFMs.
According to documents released by the Defense Ministry on December 22, the new-class FFM has a standard displacement of 4,800 tons, a slight increase from the previously mentioned 4,500 tons in the defence budget request on August 31. Mitsubishi Heavy Industries (MHI), in its proposal for the new-class FFM released by the Japanese Acquisition, Technology & Logistics Agency (ATLA) on August 25, suggested a heavier standard displacement of about 4,880 tons, a greater overall length of about 142 meters, and a wider overall beam of about 17 meters. This aligns more closely with the actual hull size, as reflected in the recent defence documents.
Despite the increase in size compared to the Mogami class, the new vessels are expected to maintain a top speed of over 30 knots, according to MHI’s proposal. Notably, the crew complement for the new class will remain at 90, the same as that of the Mogami class. Achieving this crew size is likely attributed to higher levels of automation and the implementation of extensive lean-manning concepts throughout the vessel.
Modifications of Izumo-class helicopter carriers（$298 million)
The Japan Maritime Self-Defense Force (JMSDF) has successfully secured $298 million (42.4 billion yen) for the ongoing modifications of its two Izumo-class helicopter carriers, JS Izumo and JS Kaga. The purpose of these modifications is to transform them into aircraft carriers capable of supporting Lockheed Martin F-35B fighter aircraft operations.
Of the allocated funds, $287.3 million (40.9 billion yen) will be utilized to reshape the bow section of JS Izumo’s flight deck from a trapezoid to a square shape during the fiscal year 2024. This follows the same modifications to JS Kaga’s flight deck, which are currently underway in the fiscal year 2023. Additionally, $4.2 million (600 million yen) has been earmarked to equip Izumo with a landing navigation system for F-35Bs, with Raytheon’s Joint Precision Approach and Landing System (JPALS) set to fulfil this role. Simultaneously, JS Kaga has been allocated $2.1 million (300 million yen) to undergo modifications to its satellite communicator following major upgrades in fiscal year 2023.
The JMSDF has outlined that both vessels will undergo all necessary upgrades to become light aircraft carriers capable of operating F-35B fighters by fiscal year 2027.
Development of electronic warfare aircraft ($99 million)
The Ministry of Defense (MoD) has announced plans to allocate $99 million (14.1 billion yen) for the development of an electronic warfare aircraft. This initiative aims to address the growing complexity of the electronic warfare environment and enhance capabilities in the electromagnetic domain, essential for cross-domain operations.
The electronic-warfare aircraft will be developed utilizing the framework of the Kawasaki P-1 maritime patrol aircraft (MPA). This strategic move underscores the importance of leveraging existing platforms to create specialized capabilities, aligning with the evolving needs of modern electronic warfare.
Co-development of the Glide Phase Interceptor (GPI) with the U.S.($532 million)
Japan and the United States have agreed to commence joint development of the Glide Phase Interceptor (GPI), as announced on August 18 by both the Japanese Ministry of Defense (MoD) and the U.S. Department of Defense (DoD). This collaborative effort was unveiled during a meeting between U.S. President Biden, Japanese Prime Minister Fumio Kishida, and South Korean President Yoon Suk-yeol at Camp David.
The joint development initiative is set to be completed in the early 2030s, with the Japanese side taking primary responsibility for the rocket motor and the propulsion system of the kill vehicle. This cooperative effort underscores the commitment of both nations to enhance their defence capabilities through technological advancements and collaboration in missile defence systems.
Development of a new surface-to-ship/surface-to-surface precision-guided missile ($227 million)
The ministry intends to undertake the development of a new surface-to-ship/surface-to-surface precision-guided missile with an anticipated completion by fiscal year 2030. This next-generation missile is expected to possess a significantly longer range compared to existing missiles.
During the DSEI Japan 2023 event, Kawasaki Heavy Industry (KHI) revealed a novel type of stealthy anti-ship missile referred to as the “Island Defense Anti-Ship Missile” in Japanese, denoted as “島嶼防衛用新対艦誘導弾.” This new missile is presumed to be related to the ministry’s broader plans for the development of advanced and longer-range precision-guided munitions.
Acquisition of manoeuvrable boats ($121.5million)
The Ministry of Defense (MoD) is taking steps to enhance capabilities for the swift and reliable transportation of necessary units to counter potential island invasions in the southwest region. As part of this effort, the MoD has outlined plans to procure three manoeuvrable boats in the next fiscal year, each measuring 35 meters in length.
The procurement process will involve competitive bidding after the budget is secured. To operate these new boats effectively, the MoD intends to establish a new unit named the “Self-Defense Force Maritime Transport Flotilla” (tentative) at the Japan Maritime Self-Defense Force (JMSDF) Kure Base. This flotilla, scheduled to be operational in March 2025, will function as a joint force comprising elements from the Army, navy, and Air Force, totalling about 100 members from the three services, according to the MoD.
During the DSEI Japan 2023 event, BMT showcased a model of its CAIMAN-90, which is potentially associated with this program for the procurement of manoeuvrable boats aimed at reinforcing transportation capabilities for island defence.
Construction of a new replenishment ship ($583 million)
The Ministry of Defense (MoD) has successfully secured $583 million (83 billion yen) for the construction of a 14,500-tonne replenishment ship. This new vessel aims to enhance logistical support capabilities at sea for other Japan Maritime Self-Defense Force (JMSDF) vessels in various operational scenarios. The scheduled delivery of the replenishment ship is set for fiscal year 2028, and it is intended to serve as the successor to JS Towada (AOE-422), according to the MoD’s plans.
Research on combat support multipurpose USV ($174 million)
The focus is on researching stealth Unmanned Surface Vehicles (USVs) that are selectively equipped with specific functions such as warning and surveillance, as well as anti-ship missile launch capabilities. These stealth USVs are designed to provide support to manned ships, contributing to enhanced maritime capabilities with an emphasis on advanced reconnaissance and offensive capabilities.
Development of unmanned amphibious vehicle ($145 million)
The development efforts are underway for an unmanned amphibious vehicle designed to facilitate landings from all fronts on islands. This unmanned vehicle is envisioned to play a crucial role in executing various missions, including the transportation of supplies, allowing for versatile and efficient operations in maritime environments.
Trial operation of USV (test equipment) ($114 million)
To rapidly acquire knowledge of Unmanned Surface Vehicle (USV) operations and promote the development of domestically produced USVs, the Japanese defence budget includes provisions for the procurement of USVs that have been utilized as test equipment in various countries. This initiative aims to leverage the experience and technology from existing USV models used internationally to advance the development and capabilities of Japan’s unmanned surface vehicles.
Research and development on UUV for ocean observation ($1.4 million)
To enhance the efficiency of ocean observation, efforts are being made to explore and research Unmanned Underwater Vehicles (UUVs) for tasks such as underwater topography observation and investigating acoustic characteristics. The potential introduction of UUVs is currently under consideration.
Furthermore, in pursuit of improved ocean observation capabilities, performance tests have been conducted using UUV test equipment, which was procured in Fiscal Year 2023. These tests are geared towards utilizing UUVs for tasks such as observing water temperature structure, contributing to more comprehensive and advanced oceanographic research.