Japan may be building its largest surface combatant since the Second World War, when
its huge battleships and fleet aircraft carriers roamed the Pacific Ocean.
The Japan Ministry of Defence has provided more details of its proposal to build two
huge anti-ballistic missile warships.
They are expected to have a standard displacement of around 20,000 tons – approximately twice
as much as the current AEGIS destroyers of the Japanese Maritime Self-Defence Force,
or JMSDF.
In its budget request for Fiscal Year 2023, the Defence Ministry outlined its proposal
for two new warships, which reportedly came with a combined price tag of $7.1 billion.
The overall defence budget is expected to increase from $38 billion in Fiscal Year 2022
to $40 billion in 2023.
The growth in the budget reflects an increasing desire to expand Japan’s military power,
especially its naval and air forces, for both defence as well as power projection.
Currently, the JMSDF operates eight AEGIS air warfare destroyers, including two Maya
class, two Atago class, and four Kongō class destroyers.
The Maya and the Atago are evolutions of the Kongo class, and all three classes are derivatives
of the US Navy Arleigh Burke class.
All eight AEGIS destroyers are capable of anti-ballistic missile defence to some extent,
as they are all armed with the SM-3 anti-ballistic missile interceptor.
However, there are concerns that the existing destroyers may not be sufficient for intercepting
large numbers of missiles simultaneously.
Existing missile defences may not match the recent increase in North Korean ballistic
missile capability, or the Chinese hypersonic glide vehicles found in the DF-17.
So, a new plan is needed to bolster anti-ballistic missile defence.
Since 2014, Japan has been thinking about installing two ground-based ballistic missile
defence system, called AEGIS Ashore.
This project was jointly undertaken by Raytheon and Mitsubishi Heavy Industries.
However, in 2020 the Japanese Government officially halted the project, supposedly because of
concerns that the booster for the SM-3 interceptors could land in populated areas, and cause injuries
or even fatalities.
There was also concern around the potential health impact of the radiation from AEGIS
Ashore’s powerful radar.
That said, Japan did purchase the AN/SPY-7 Long Range Discrimination Radar designed for
defence against ballistic missiles.
These are the radars that were originally going to be used in the Aegis Ashore.
They shall be used on the new 20,000-ton destroyers instead.
According to the Japanese newspaper the Nikkei, the expected dimension of the new warship
is a length of around 210 metres and a width of 40 metres.
This is much larger than the existing Maya class destroyer, which is 170 metres long
and only 22 metres wide.
Clearly, the new warships are going to be quite wide, even more so than they are long.
Previous report suggested that the new ships might be built on a modified hull of the Maya
class, but clearly with such a massive difference in the actual dimension compared to the Maya,
the new warships should be built on a different hull.
In fact, in terms of size, the new anti-missile warships would be more comparable to the Izumo
class de facto helicopter carriers.
They are currently the JMSDF’s largest warships, and have an empty displacement of just under
20,000 tons, and 27,000 tons fully loaded.
It is unclear what the new ships will actually look like.
While they have been described in the Japanese media as ‘super destroyers’, there is
growing expectations that they will not use the same kind of design as the AEGIS warships.
Rather, they may be more similar to the Izumo class, taking advantage of their larger width
and improved stability.
This is a key factor to the optimal performance of the AN/SPY-7 radar.
Similar thinking also underpinned the US Ballistic Missile Defence Warship, designed on the basis
of the same hull as the existing San Antonio class landing platform dock.
The goal was to provide a specialised warship focused exclusively on ballistic missile defence
than the existing Arleigh Burke class destroyers.
The warships should have vertical launching systems to carry the Standard Missile-3 Block
2A interceptors, which offer a wider envelope of engagement than currently fielded SM-3
variants on the Japanese destroyers.
The Standard Missile-3 Block 2A are better able to tackle a greater variety of missile
threats from multiple angles.
The Japanese Defence Minister also claimed that the new warships would have the capability
to counter hypersonic glide weapons.
This is of course referring to the Chinese DF-17 anti-ship ballistic missile, with a
hypersonic glide vehicle as the warhead, and also a clear reference to the Russian Zircon
hypersonic cruise missile.
According to Japanese media, the capability to intercept hypersonic glide weapons would
“be added later,” but no other details were provided.
Personally, I’m pretty sceptical of whether they can do this.
The technical challenges involved is immense.
We are talking about intercepting projectiles that fly at more than five times the speed
of sound, with the ability to manoeuvre freely while doing so, and which may be invisible
to existing radar systems.
So, we’ll see if Japan comes up with a credible counter to hypersonic weapons.
Lastly, make no mistakes.
While Japan emphasised the ballistic missile threat posed by North Korea, the proposal
for the 20,000 plus ton warships definitely has China in mind.
The new missile defence ships can be positioned in the Sea of Japan to intercept North Korean
missiles, or they can deploy to the East China Sea, or even the South China Sea.
They can shield a Japanese naval taskforce from Chinese ballistic missiles in potentially
hostile waters.
Unlike a ground-based defence system, warships can go anywhere and project power against
anyone if so desired, not just North Korea.
Additionally, simply by having two anti-ballistic missile warships in the Sea of Japan would
allow the other Japanese destroyers to focus on the Chinese Navy.
In fact, the new ships could very well be armed with offensive weapons.
Japanese media speculated that a so-called “counterattack capability” could be added,
in the form of the Type 12 anti-ship and land-attack missile.
This would potentially have a range of over 600 miles.
Note the information so far reflect only a draft plan, and there are likely to be changes
depending on technical or funding considerations.
Indeed, the design is contingent on the Defence Ministry actually receiving the necessary
funding for construction to go forward.
Anyway, current plans expect the first of the new warships to be commissioned in late
2027, with the second ship in late 2028.