September 29, 2021

Some Major Japanese Politicians Talking Nuke Propelled Subs

The AUKUS agreement effectively removes the legal taboo of the US or UK exporting 93+% weapons grade nuclear reactor HEU to Australia. By this taboo removal this trends toward legitimizing nuclear submarine propulsion for Japan. 

Some senior Japanese political leaders are now talking of possible future Japanese nuclear propelled submarines quite openly.

From the late 1960s Japan completed the nuclear propelled ship Mutsu with a Japanese built miniaturized reactor. Japan has maintained a highly developed conventional sub industry and a nuclear industrial base. 

Rahul Kumar, for India's daijiworld, September 28, 2021 has written an excellent commentary on the Japanese leaders' statements

"After AUKUS, Japan debates if it too should have nuclear-powered submarines"

New Delhi, Sep 28: The AUKUS deal between the US, Australia and the UK to provide Australia with nuclear-powered submarines to take on China in the Indo-Pacific has caused rumblings in Japan.

Japanese politicians are debating whether Japan should also possess one. Japan goes to elections in November [2021] and the nuclear submarine for Australia, coupled with Chinese aggression in the region, has become a political issue.

Taro Kono - Japan's administrative reform minister, who is likely to lead the ruling party - Liberal Democratic Party (LDP), and may become the Prime Minister after Yoshihide Suga, is in favour of acquiring the submarines. In a TV debate on Sunday, he said: "As a capability, it is very important for Japan to have nuclear submarines".

Nikkei Asia reports that former internal affairs minister Sanae Takaichi endorsed the idea. Talking about the positives of owning a nuclear-powered submarine, she said that Japan would be able to travel longer with such a machine. These submarines are preferred because these are quieter, have a longer range and remain underwater for long.

Not everyone within the party endorses the idea.

Fumio Kishida, former policy chief of the LDP [and on Sept 29, 2021 appointed Leader of the LDP] feels that the country's security needs are not such that it needs to go far out from Tokyo's shores. He, therefore, does not feel the need for the Japanese Self Defence Forces to acquire a nuclear-powered submarine.

The fast-track geo-political changes in the seas around Japan has given fuel to much debate within the country.

China's rise as an aggressive economic and military power is making Tokyo uncomfortable. With frequent war cries about annexing Taiwan, Beijing has given much stress to Japan which feels that China might invade Japanese islands as well. The China factor has forced a worried Japan to rethink its military strategy.

The slow but continuous process through which China has usurped a number of reefs and islands in the South China Sea has made Japan and other countries nervous.

In the last few months Japan has been regularly highlighting Chinese aggression in the region. A white paper on defence accepted Taiwan as a separate territory from China. Tokyo has gone to the extent of saying that it will join forces with Taiwan against Chinese aggression."

Pete Comment

With Fumio Kishida likely to become Japan's next Prime Minister in November 2021 Japan may not "go nuclear sub" in the short-medium term. But AUKUS' lifting of the nuke propelled sub taboo, now appears to be permitting a trend. Previously unthinkable pro-nuclear sub statements are now being made by major Japanese politicians.

3 comments:

Anonymous said...

Can anyone - especially Japanese commenters

shed light on Japan's "white paper on defense." referred to in the Rahul Kumar article at https://www.daijiworld.com/news/newsDisplay?newsID=877940

This is regarding Japan "will join forces to defend Taiwan..."

Its a long way from a white paper to a solid treaty, especially given Japanese constitution and Japanese domestic politics, but this may be a trial balloon to Japanese constituencies to check for possible reactions. Signals (if any) to US, Australia, UK, India are probably on more secure channels.

Japan by itself may not be enough to deter China, but if joined AUKUS and India for joint patrols in Taiwan straits, may be a viable deterrent.

Still, hopes to contain China and prevent war on Taiwan seem a bit brighter.

Gessler said...

I do tend to agree with Mr. Fumio Kishida, in all likelihood the next Prime Minister of Japan.

While Japan might be more than capable of delivering on a domestically-built SSN (or even SSBN) program within a reasonable amount of time, the real question to be asked by internal decision makers will revolve around "do we need it?", "how much will it cost in time & money?" and "can we spend that time & money on something more important for national defence?"

SSN compared to SSK/SSP can be boiled down to three main advantages (among others of course):

a) How far it can travel
b) How fast it can conduct said travel
c) How it can conduct said travel at said speed without needing to surface

Japan's geography & proximity to China negates many of the range advantages that made SSN so lucrative (and frankly, so necessary) for Australia. But an SSN would still be of tremendous use in chasing down & hunting surface task forces/carrier groups like no diesel-powered sub ever can.

So that leaves this question for the Japanese:

What should we seek to do with our submarines?

a) Use them for lying in wait & springing ambushes on Chinese surface or sub-surface elements as they try to navigate critical chokepoints in the First Island Chain, while leaving the security of the high seas & the role of keeping a hair trigger pointed on the Chinese SSBNs to the Americans?

OR

b) Use them for chasing & hunting down Chinese ships & subs on the high seas in the waters between the First and Second Island Chains, if not even outside of that...while also assuming the role of constantly monitoring & tailing Chinese SSBNs wherever they might go?

If the Japanese decide Option A, then I'd venture to say their highly advanced conventional submarine industry backed by highly advanced Lithium-Ion Battery (LIB) development should prove largely sufficient for their needs.

If they go with Option B, then they will need SSNs. And lots of them (at least 6-12), which also means lots of time & money.

...which brings me back to this:

"can we spend that time & money on something more important for national defence?"

Considering they have the option of relying on the Americans for hunter-killer roles against Chinese subs, would the Japanese be better served by pursuing an SSBN program ahead of a potential SSN program?

Kind of like India did (though in our case, it was more a result of there not being any immediate SSN threat in the area which allowed us to concentrate on creating a deterrence platform first). Once the SSBN platform is ready, making an SSN version by omitting the missile compartment should be relatively straightforward if they choose a 'common platform' type design from the start.

The Japanese may choose to equip it with conventional ballistic or cruise missiles like the Koreans are doing on their diesel boats, which would then set the stage for swapping out the armament for nuclear warhead-equipped missiles in the event Japan decides its time to 'Breakout'.

Just thinking out loud here, considering all possibilities.

Pete said...

Thanks Gessler

In terms of major powers choosing to make enough funding available for nuclear propulsion I shift in time and place to the UK and France deciding to build the most effective second strike deterrent https://en.wikipedia.org/wiki/Second_strike against USSR/Warsaw Pact nuclear weapons.

I'm arguing - your nuclear powered nuclear weapon platform will always constitute a more effective/secure second strike deterrent no matter the distance of your national borders from your nuclear armed enemies.

From 1949, when the USSR exploded its first nuclear weapon, the UK and especially France noted that their countries were only short distances away from Warsaw Pact countries hosting USSR/Russian nuclear weapons. France was only a few 100 kms away from Russian nuclear weapon hosting East Germany.

Counter-intuitively both France and the UK eventually arrived at the conclusion that nuclear propelled SSBNs set back in the Atlantic constituded the best second strike deterrents against Russian nuclear weapons.

This "set back" SSBN concept can be applied to South Korea, Japan and even Taiwan. ie: a nuclear powered nuclear weapon platform will always constitute a more effective/secure second strike deterrent no matter the distance of your national borders from your nuclear armed enemies.

To protect your SSBNs (especially moving to/from your submarine base) the main threat is enemy SSNs. The speeds involved rule out SSKs being the most effective ASW subs against enemy SSNs. Hence half the job justifying wour SSNs is protection of your SSBNs. This also part explains why the US, UK and France have long decided NOT to field SSKs.