Tomahawks are arriving, hypersonic missiles are in development, and nuclear submarines are under consideration. How far will Tokyo’s military buildup go?
In recent months, there’s been a distinct sense of ‘historical déjà vu’ – from Germany’s interest in long-range missiles to the development of hypersonic missile technologies in Japan. The first question that comes to mind is whether revanchism is emerging more than 80 years after the defeat of the fascists and militarists in WWII. However, this question is quite complicated, so for now, we will focus on a more practical issue: Japan’s military-technical buildup. Below, we will attempt to assess the significance of this shift in Japan’s strike capabilities and understand the direction in which the country is heading.
By the end of the 20th century, Japan had become one of the strongest and most loyal allies of the US in the Pacific region. The Japan Self-Defense Forces are equipped with American aircraft, missiles, interceptors, and other weapons. Japan is the first and to date the only country in the world to manufacture Patriot surface-to-air missiles under license, and it is the first foreign recipient of Tomahawk subsonic cruise missiles.
On July 29, 2026, the first test launches of Tomahawk cruise missiles were conducted in the Pacific Ocean from the Kongo-class guided-missile destroyer JS Chokai, equipped with the Aegis system. These tests mark the beginning of the Japanese Navy’s adoption of American long-range cruise missiles. The program to acquire these missiles is quite ambitious: Japan plans to equip four additional Aegis-capable destroyers – JS Kirishima, JS Haguro, JS Myoko, and JS Atago—with these state-of-the-art missiles, with the long-term goal of upgrading all other destroyers of this class. In total, the acquisition of 400 missiles (Block IV and Block V variants) is planned by the end of the 2027 fiscal year. This arsenal significantly alters the capabilities of the Japanese Navy, given that such cruise missiles can strike targets at ranges of up to 1,600 km. Furthermore, this is merely an interim solution pending the adoption of domestically developed missiles with similar or superior specifications.
Japan is currently working on several missile projects, with a particular focus on hypersonic technologies. Japan has already concluded an agreement with Australia to conduct joint tests at Australian missile ranges, which offer the necessary facilities for testing long-range missiles; the development of several strike missile projects is scheduled to begin in 2027.
One of the major initiatives is the project to develop a submarine-launched hypersonic missile capable of striking land-based targets. The missile is expected to be versatile, capable of being deployed from both Japanese Navy submarines and surface ships. Japan justifies the deployment of such missiles on submarines by citing the need for retaliatory strike capabilities in the event of an external attack. Naturally, Japan is pointing to the growing capabilities of China’s navy and missile forces. For its part, China is also actively enhancing its capabilities in light of a possible confrontation with the US and Japan.
While the hypersonic missile project is currently in the preliminary design phase, it draws upon Japan’s existing experience in developing various types of missiles and submarine-based vertical launch systems, as well as ambitious programs to build new missile-equipped vessels and, eventually, nuclear-powered submarines. In 2023, the Japanese Ministry of Defense signed a contract with Mitsubishi Heavy Industries for the development of a submarine-launched guided missile; a separate official program launched that same year is focused on developing an indigenous hypersonic guided missile; the work is set to continue through 2031. These programs are essentially aimed at creating preliminary designs for future missiles and developing hypersonic technologies in general; however, following the research phase, Japan will move on to developing specific missile models. The potential for this already exists.
What about launch platforms? Currently, the Japanese Navy operates several Aegis-equipped destroyers and non-nuclear submarines; they could carry a limited number of missiles. However, this would not be sufficient for mass deployment.
In 2027, the Japan Maritime Self-Defense Force is set to commission the lead ASEV-class destroyer into service. Though the destroyer is modestly designated as a “missile defense ship,” it is in reality a guided-missile cruiser. It will measure approximately 189 meters in length and 25 meters in beam, with a standard displacement of around 12,000 tons. This makes it significantly larger than the current Maya-class destroyers or even US Ticonderoga-class guided-missile cruisers. Each vessel will carry 128 modular vertical launch system (VLS) cells capable of housing Standard Missile shipborne guided missiles, anti-ship missiles, and strike missiles – ranging from the Tomahawk to future domestically-developed hypersonic missiles. Plans currently call for the construction of two such ships. The speed of construction is impressive: one ship is set to be built in three years. This will be the most heavily armed missile-carrying warship in the Pacific.
And what about nuclear-powered submarines? Recently, Japan’s Ministry of Defense officially included nuclear-powered submarines in its defense posture review, paving the way for Tokyo to assess the feasibility of building such vessels alongside its conventional fleet. Strict restrictions on the military use of nuclear energy had previously been in place in Japan, but in regard to submarines, this particular constraint is now being quietly lifted.
Naturally, such a move would logically expand Japan’s underwater operations in the Western Pacific; from a shipbuilding perspective, Japan certainly has the capacity for it. Nuclear propulsion would allow Japanese submarines to remain submerged for virtually unlimited periods, effectively neutralizing potential Chinese undersea superiority. The US would, of course, be Japan’s primary industrial partner in this endeavor, though the UK or France could also share their expertise in nuclear submarine construction. Following Japan’s lead, South Korea is also considering the development of nuclear submarines. While Japan blames China, South Korea cites the threat of North Korea. In both cases, it looks like the arms industry lobby is actively seeking an outlet for its manufacturing capacity.
But that’s not all – there is also the aviation sector. Alongside the UK and Italy, Japan is participating in the Global Combat Air Program (GCAP) to develop a sixth-generation fighter jet. The program aims to finalize the aircraft’s requirements and technical specifications by the end of 2027. Furthermore, the Excalibur flying test laboratory and the demonstrator aircraft are scheduled to begin testing by the end of 2027. These efforts are critically important for Japan, as it decides which joint initiative to participate in and whether it should launch its own program to develop a next-generation fighter jet
Therefore, by the 2040s-2050s, the capabilities of the Japanese armed forces could change beyond recognition. Japan could possess nuclear-powered submarines, a missile-armed fleet, a modern air force, ground-launched and subsonic long-range hypersonic and cruise missiles.
Finally, experts believe that, if necessary, Japan could quickly produce nuclear weapons. This would take only a few months. The country possesses a highly developed nuclear industry and nuclear energy sector – with stockpiles of plutonium and other materials, as well as all the requisite technologies. Japan also has nuclear weapons delivery systems at its disposal. In short, all the prerequisites are in place, though strict constitutional constraints currently remain in effect. However, if one threshold is crossed and the decision to build nuclear submarines is made, one might expect this nuclear trend to continue in the direction of classified research and weapons development. A highly advanced nation like Japan could develop nuclear weapons quickly and covertly.
That’s the ‘samurai sword’ slowly but surely emerging from the East. How should we react to it? Sound the alarm and deploy weapons, or call for peace and dispatch ballet troupes? Perhaps, both. Let’s hope that we’ll never have to use the weapons, but be prepared just in case; as for ballet, it’s always a good idea.
