Japan not ruling out Nuclear Subs after US offers positive view

Jesse Johnson, Staff Writer for the Japan Times, on September 11, 2026 reports

https://www.japantimes.co.jp/news/2026/09/11/japan/koizumi-japan-us-nuclear-submarines/

Defense Minister Shinjiro Koizumi has said that Japan is keeping all options on the table when it comes to discussions of Japan acquiring nuclear-powered submarines. | JIJI
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...Japan not ruling out nuclear subs, days after U.S. offers positive view

Defense Minister Shinjiro Koizumi on [

Sept 11, 2026] reiterated that Japan is not ruling out acquiring nuclear-powered submarines, days after a U.S. Navy official reportedly offered a positive assessment of the move.

“Regarding nuclear-powered submarines, we will proceed with our consideration of not ruling them out as an option,” Koizumi told a regular news conference. Tokyo is weighing acquiring such submarines in revisions to its three key security documents set to come by the year’s end.

Koizumi’s remarks came after an unidentified U.S. Navy official [at Pearl Harbor - see Trump (diplomatic as ever's) revenge on Japan], citing Tokyo’s expertise in nuclear energy technology, told Japanese and South Korean media this week that Tokyo should consider acquiring nuclear submarines.

Asked about how the vessels might fit into Japan’s security strategy, the defense chief noted the pros and cons, saying that while nuclear-powered submarines are capable of extended patrols and are said to have several times the speed of conventionally powered submarines, they are less quiet underwater, expensive and require specialized expertise for maintenance, repair and operation.

Japan currently operates a fleet of 23 diesel-electric attack submarines, but has long avoided the more expensive and politically fraught option of nuclear-powered vessels.

Calls for Tokyo to acquire nuclear boats gained steam after an expert panel recommended in September last year that Tokyo develop vessels with “next-generation” power sources and vertical launching systems for long-range missiles. The ruling Liberal Democratic Party-Japan Innovation Party bloc effectively codified this push in their October coalition agreement.

Although neither the expert panel nor the coalition deal directly mentioned nuclear-powered submarines, Koizumi and other Japanese officials have repeatedly refused to rule out any options when it comes to nuclear submarines, as Tokyo looks to boost its defense capabilities.

Koizumi added to the speculation in November, when he touched on South Korea’s deal with the U.S. to secure nuclear vessels, noting that “all the surrounding countries have nuclear submarines.”

In June, the JIP also reignited the debate when it submitted a proposal to the government that called for the swift introduction of nuclear-powered submarines, citing China’s constant naval expansion into the Pacific.

The Chinese Navy is moving toward an all-nuclear-powered submarine fleet, U.S. naval officials say, a monumental shift that will give ammunition to proponents of Japan developing its own nuclear subs.

US says South Korea doesn’t need a nuclear submarine if sub never leaves Korean area

South Korea's HANKYOREH on September 11, 2026 reported 

https://english.hani.co.kr/arti/english_edition/e_international/1277423.html

Seoul shouldn’t pursue nuclear submarine purely as ‘status symbol,’ says US Navy official

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The official suggested South Korea needs to “find the right reason” to have a nuclear-powered submarine

A high-ranking US Navy official stressed that South Korea’s push to acquire nuclear-powered submarines must be backed by a clear strategic need to operate beyond the Korean Peninsula, rather than a desire for a mere “status symbol.”

The official also suggested that while the US’ recent scaling back of joint military exercises with South Korea does not necessarily weaken deterrence against North Korea, Pyongyang could misread those changes.

Speaking with the Hankyoreh and other foreign correspondents on Wednesday, the US Navy official said that Washington had indicated it was “happy to help” Korea acquire nuclear-powered submarines but noted that “you don’t need a nuclear submarine if you never leave the Korean area.”

“Korea’s got to find the right reason to have a nuclear submarine,” the official said. “We can’t tell you what that reason is.”

“If Korea is buying it because it’s a status symbol, then that’s the wrong reason,” the official added.

The remarks suggest that before committing the enormous sums required to field nuclear-powered submarines, Seoul should first articulate a strategic requirement, such as operations beyond the Korean Peninsula.

In a follow-up explanation after the briefing, the US Navy said the official’s point was that decisions to acquire military assets should be based on national security needs and actual operational use.

In the briefing, the Navy official referred to previous calls by US Chief of Naval Operations Adm. Daryl Caudle for the Korean Navy to expand its operations beyond the region.

During a visit to Korea last November, Caudle said that using a Korean nuclear-powered submarine “to counter China” would be “a natural expectation.”

The latest remarks strongly suggest that the US Navy thinks Korea’s acquisition of nuclear-powered submarines should be tied not simply to deterring North Korea around the Korean Peninsula, but to an expanded role for the South Korean Navy across the Indo-Pacific, which would include deterring China.

Asked whether Russian assistance could strengthen North Korea’s submarine technology and capabilities, the official noted that “having submarines does not mean you know how to operate them.”

“The Russians helping North Koreans is concerning,” he said, while adding that “we haven’t seen anything yet that makes us worried.”

The official’s apparent point was that the ability to effectively operate submarines can be as important as their numerical strength or capabilities.

In a follow-up explanation after the briefing, the US Navy said the official was conveying that advanced underwater warfare capabilities require specialized training, maintenance, infrastructure and operational proficiency to be used effectively.

The official also commented on the temporary diversion of US aircraft carriers from the Pacific to the Middle East conflict by stressing that deterrence is about more than numbers alone.

In the same briefing, the official was asked about how recent reductions and adjustments to ROK-US joint military exercises might impact deterrence against North Korea. “I think that the ROK military can handle the North Koreans without any trouble,” he said, while arguing that changes in troop levels or military exercises do not necessarily downgrade military capability.

But the official noted that these changes “might have an impact” on what Kim Jong-un thinks, with the implicit warning that Pyongyang could read them as a sign of diminished US strength.

In regard to challenges faced by the US in its capacity “to build ships and to maintain them,” the official described Korean shipbuilders as “some of the best in the world” and stressed the need for cooperation.

A related question that came up is whether the Trump administration’s “Bridge Strategy” — under which two ships would first be built in Korea or another foreign country while the US works to expand its production capacity — would be too slow to build up the fleet.

“Late or never, right?” the official said.

“Going the way we were, we never would do it,” he said, suggesting that under the previous approach, production capacity might never be expanded.

By Kim Won-chul, Washington correspondent

Singapore Navy: New MRCVs, OPVs, 218SG subs & Landing Craft under construction

Republic of Singapore picture of third future MRCV (Vigilance) carried by Naval News September 3, 2026
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The Republic of Singapore Navy (RSN) has two major new vessel classes currently under construction: the Victory class Multi-Role Combat Vessels (MRCVs) and the unnamed class of Offshore Patrol Vessels (OPVs).

These vessels, along with Singapore's new, eventually 6 x Invincible-class/Type 218SG submarines, will sharply increase the tonnage and capability of Singapore's Navy. 

Multi-Role Combat Vessels (MRCVs)

Singapore's ST Engineering Marine is building 6 large 8,400 tonne Victory-class MRCVs to replace the 6 aging 600 tonne, confusingly also called "Victory-class" missile corvettes.

Current Status: The first MRCV (Victory) was launched in late 2025, the second ship (Valour) was launched on July 23, 2026, and the keel for the third ship (Vigilance) (see artwork above) was laid down on September 3, 2026. 
Delivery: Scheduled for progressive delivery starting in 2028 through 2030. 
Design & Capabilities: Displacing roughly 8,000 to 8,400 tonnes and measuring 150 meters long, these advanced warships function as "motherships" capable of operating unmanned aerial, surface, and underwater systems. They feature high automation requiring a crew of fewer than 100 sailors. 

https://www.navalnews.com/naval-news/2026/09/singapore-lays-keel-for-third-multi-role-combat-vessel/

Singapore navy launches first of six MRCVs. Reports Channel News Asia (CNA) on October 22, 2025.
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Offshore Patrol Vessels (OPVs)

Singapore is also procuring a class of four new OPVs, possibly based on the German 1,900 tonne Potsdam-class patrol boat, to succeed various smaller vessels including the 500 tonne Sentinel-class maritime security and response vessels (MRSVs).

Current Status: Designed by German firm Fassmer and built by Western Baltic Shipyard before final outfitting.
Delivery: Deliveries to the RSN are planned to begin progressively from 2028.

New Landing Craft Prototypes

In August 2026, Singapore awarded a contract to Penguin Shipyard International to build two new landing craft prototypes (with the Fast Craft Utility (FCU) with an 18 tonne load perhaps displacing 45 tonnes fully loaded?) to support ship-to-shore operations and evaluate evolving defense requirements. 

Singapore orders new landing craft prototypes for its navy. See photo and details at Asian Military Review, August 26, 2026.
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Article assisted by Google AI, September 8, 2026.

More Bang for the Buck! East Coast Australian Nuclear Submarine Base

For the small fee of one standard Henderson Defence Precinct $70 Billion infrastructure project - communities with east coast nuclear submarine base aspirations are competing for the rights to host five AUKUS nuclear submarines.

Newcastle, Port Kembla-Wollongong and Brisbane are all third rate - as these ports as they have 100,000s of polluted humans. Not a problem with Twofold Bay south of Eden, Far South Coast NSW. 

Twofold is pristine, has whales and a small remote population of people, not yet irradiated, third deepest natural harbour (pre-explosion) in the Southern Hemisphere and few NIMBY or NOTEY environmentalists. Once the current residents are driven out by Dr Strangeloves Twofold would welcome Virginia-class Submarines with Highly Enriched (Weapons Grade) Uranium reactors.

Such reactors have advantages in that just one, safely cut into, would yield sufficient nuclear explosives for 20 Australian atom bombs. This would save Australia $1 Trillion in atomic bomb development and usher out any thought of a nuclear free South Pacific (the Virginia reactors are literally slow action nuclear weapons) while yielding squadrons of nuclear bombers.

​"Huge waste’ of defence budget to build AUKUS-class submarines in Australia"

Australia's The Weekly Times on September 4, 2026 reported : ​

..."Former [long term] foreign minister Alexander Downer believes that building AUKUS-class submarines in Adelaide is a “huge waste” of Australia’s defence budget.​“In time the AUKUS-class submarine…will be built, we may as well just buy them off the shelf from the UK where they already have the capacity to build nuclear submarines rather than spending a 30 per cent or 40 per cent premium building them in Adelaide,” Mr Downer told News24 host Chris Kenny.

[Downer added] “Give South Australia some compensatory money, but honestly, it’s just a huge waste of the defence budget to be building the submarines here in Australia. “We don’t build F-35s in Australia for good reason. “When it comes to defence, focus on defence, don’t focus on votes in Adelaide suburbs.”

Japan's Type-25 HVGP & HCM Hypersonic Weapons: Japan hypersonics in Australia

Japan’s new Type 25 hypersonic missile family are changing the operational picture in the region from the 25SSM hypersonic cruise missile to the 25HGP hypersonic glide variant.

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Comments by wispywood2344 from Japan on August 29, 2026 and September 1, 2026, August prompted me to conclude Japan is rapidly maturing hypersonic weapons. 

I then researched this subject using AI Google analysis on September 3, 2026. Using and presenting AI effectively and critically takes experience:

Japan has begun deploying its first stand-off hypervelocity weapons while actively developing advanced hypersonic glide and cruise missile technologies.

Key Weapon Systems

• Type-25 HVGP (Block 1)[aka 25HGP ] : Japan deployed this hypervelocity gliding projectile for island defense, featuring a range of several hundred kilometers. [1, 2]
• HVGP Block 2: An advanced variant with an extended range targeting roughly 2,000 kilometers, scheduled for deployment in the 2030s. [1]
• Scramjet Hypersonic Cruise Missile (HCM) [aka 25SSM ] : Japan is researching scramjet-powered engines for future compact, high-speed cruise missiles, including potential underwater launch applications. [1]

Strategic & Technological Developments

• Underwater Launch Plans: Japan's FY2027 defense budget request includes unpriced funding to research submarine- or modular unmanned underwater vehicle (UUV)-launched long-range strike and hypersonic capabilities. [1, 2]
• Testing in Australia: Japan and Australia announced a [new hyperlink bilateral agreement ] allowing the Japan Self-Defense Forces to test [see 5(d)] long-range stand-off and hypersonic missiles on Australian military ranges over the coming decade. [1, 2]
• Space-Based Tracking: Japan is developing low Earth orbit (LEO) infrared sensor payloads (such as pathfinder experiments aboard JAXA's HTVX1 spacecraft) to continuously detect and track manoeuvring hypersonic threats. [1]

The specific strategic implications for regional security

1. Complicating PLA Operations in the First Island Chain

• Targeting Amphibious Fleets: Japan’s hypersonic weapons are optimised for anti-ship strikes. This directly threatens China’s People's Liberation Army (PLA) surface combatants and amphibious assault groups. [1, 2]
• Disrupting Taiwan Conflict Planning: In a potential Taiwan Strait conflict, Japan could hold PLA naval forces at risk from a distance, restricting their freedom of movement within the critical First Island Chain and the Miyako Strait. [1, 2]
• Mitigating Airbase Vulnerability: Japan faces a severe shortage of hardened aircraft shelters, making its air forces vulnerable to pre-emptive strikes. Deploying mobile, ground-launched HVGPs to areas like Kyūshū, alongside stealthy underwater-launched hypersonic variants from submarines or unmanned underwater vehicles (UUVs), ensures a highly survivable strike capability that China cannot easily suppress. [1, 2, 4, 5, 6]

2. Shifting the Interconnected Threat Dynamics (China, Russia, North Korea)

• Breaking the "Shield Only" Posture: For decades, regional adversaries operated under the assumption that Japan would act only as a "shield" while the United States acted as the "spear". Japan’s ability to conduct independent, high-speed, precision strikes against launch sites or command nodes fundamentally alters adversary risk calculations. [1, 2]
• Countering Coordinated Pressure: Tokyo views the military activities of China, Russia, and North Korea as an interconnected security challenge (such as joint Sino-Russian strategic bomber patrols and North Korean missile tests). Hypersonic weapons provide a flexible, rapid-response option to counter multi-front intimidation. [1]

3. Escalation Risks and Compressed Decision Windows

• Incentives for Pre-emption: Because hypersonic missiles travel at speeds exceeding Mach 5 and follow unpredictable, maneuvering flight paths, they leave adversaries with virtually zero reaction time. This compresses the decision-making windows for all regional actors, which analysts warn could increase the risk of miscalculation or spark pre-emptive strikes during a crisis.
• Intelligence Dependency: For the immediate future, Japan remains heavily reliant on US intelligence, surveillance, and reconnaissance (ISR) for mid-flight targeting coordination in access-denied areas. This deepens bilateral operational integration but anchors Japan firmly within the US-led alliance's escalatory ladder. [1, 2, 3, 4]

4. Anchoring Multi-National Mini-Lateral Alliances

• The Australia-Japan Defense Axis: Japan’s decision to test its long-range stand-off and hypersonic missiles at remote military ranges in Australia marks an unprecedented expansion of security ties. This shifts their relationship from diplomatic alignment into an integrated, practical defense partnership.
• [new hyperlink] AUKUS Pillar II Integration: Japan's rapid domestic hypersonic advancements reinforce the momentum to formally integrate Tokyo into AUKUS Pillar II. This collaboration accelerates the co-development of advanced underwater capabilities, artificial intelligence, and next-generation hypersonic technologies among Australia, the US, the UK, and Japan. [1, 2]