Former People Power Party lawmaker Thae Yong-ho speaks during an appearance on Asia Today TV’s “Shin Yul’s Political Check” on Dec. 29. Photo by Asia Today
Dec. 29 (Asia Today) — Former People Power Party lawmaker Thae Yong-ho said Monday that North Korea is likely to build a nuclear-powered submarine before South Korea, citing Pyongyang’s ability to bypass lengthy legislative and administrative processes.
Thae made the remarks during an appearance on Asia Today TV’s political talk show Shin Yul’s Political Check. He was commenting on North Korea’s stated goal of developing a nuclear-powered strategic submarine as part of its five major defense modernization tasks.
“North Korea’s objective is to create a nuclear threat that the United States would perceive as credible,” Thae said. He added, however, that Washington still does not view Pyongyang’s nuclear capabilities as an immediate existential threat.
He said a land-based nuclear missile launched from North Korea would take about an hour to reach the United States and could be intercepted or neutralized through a preemptive strike. “That’s why North Korea is trying to develop a method to hide in the depths of the ocean and launch closer to U.S. shores,” he said, adding that Pyongyang ultimately seeks recognition as a nuclear-armed state.
“North Korea lies a lot and engages in bluster,” Thae said. “But when you look back, they usually end up building what they say they will. The quality may not be sophisticated, but they get it done. A nuclear submarine is just a matter of time.”
Asked whether South Korea or North Korea would succeed first, Thae said he believed the North would do so earlier. He noted that while South Korea has much of the necessary technology, building a nuclear-powered submarine would require years of preparation, legislative approval and negotiations, particularly with the United States.
“Even if it were built at a U.S. shipyard, the infrastructure alone could take five years to prepare,” he said. He added that fuel transfer issues and U.S. legislative approval would also pose major hurdles. “We are a democracy, so procedures take time. North Korea can simply cobble something together with Russia, but we cannot.”
Thae also said North Korea has not yet completed its submarine-launched ballistic missile technology. He noted that while the North has displayed launches from barges, it has not conducted a confirmed underwater launch since unveiling a nuclear attack submarine in September 2023.
“If they had mastered the technology, they would have demonstrated it by now,” he said, adding that firing missiles underwater while maintaining submarine stability is highly complex.
Thae also predicted that North Korea’s internal power structure could move into what he described as an “era of Ri Sol-ju,” referring to Kim Jong-un’s wife. He said Kim’s daughter, Kim Ju-ae’s public appearances appear symbolic rather than indicative of an imminent female successor.
Turning to South Korea’s decision to allow limited public access to Rodong Sinmun, Thae downplayed concerns about social impact. He said the newspaper is only available in restricted settings such as libraries and is not widely read even inside North Korea.
“In North Korea, officials are forced to read it during designated morning sessions,” he said. “Who would read it here, and how many people would bother? There won’t be major social repercussions.”
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Satellite imagery is now available showing the aftermath of a Ukrainian attack yesterday on a Russian Navy Improved Kilo class diesel-electric submarine in the Black Sea naval stronghold of Novorossiysk. The Security Service of Ukraine (SBU) claimed that this was the first attack against a Russian vessel using an uncrewed underwater vehicle (UUV). The operation could also mark the historic first successful use of a UUV as an anti-ship weapon, but the actual level of damage inflicted on the submarine remains unclear. Readers can first get up to date on the attack in our initial reporting here.
TWZ obtained satellite images of where the attack occurred in Novorossiysk from Vantor (formerly Maxar Technologies). Additional imagery from Planet Labs has also been circulating online.
The satellite imagery confirms that the UUV — named by the SBU as a Sub Sea Baby, a previously unknown type — detonated off the stern of the submarine, which was at a pier in the port of Novorossiysk. A substantial chunk of the pier itself was destroyed in the attack. This all aligns with video footage shot during the attack from a position on the ground nearby, which the SBU released yesterday.
The post-strike imagery shows that the Improved Kilo class submarine, also known as a Project 636.3 Varshavyanka class type, is in the same position as it was before the attack. Two other submarines that were moored nearby when the attack occured have moved. Other submarines and ships are still in the moorings, including on the outside edge of the damaged pier.
Some of the imagery available now suggests that the submarine that was attacked may now be sitting lower in the water, but that can’t be readily confirmed. Any damage below the waterline would also not be visible in the images. At the same time, there are also no clear signs of any emergency measures having been taken to keep it afloat, or to contain the leakage of oil or other potentially hazardous fluids, as one might expect to see if the damage was severe.
Based on the estimated length of what is visible of the submarine, some observers have noted that the epicenter of the explosion looks to have been less than 65 feet from the stern. The size and configuration of the Sub Sea Baby’s warhead, as well as other details about the UUV and its capabilities, remain scant.
Satellite imagery shows the aftermath of a strike by a Sea Baby underwater drone against a submarine pier in the port of Novorossiysk.
— Status-6 (Military & Conflict News) (@Archer83Able) December 16, 2025
It’s also worth noting that wider views of the port of Novorossiysk following the attack show four Project 636 submarines still present. There is nothing definitive to indicate that the targeted boat might have been replaced by another to conceal the extent of the damage.
Satellite reveals that four Kilo-class submarines are docked at the Novorossisk port in Russia. One of them appears to have a slightly different waterline compared to the other three. Ukraine claimed that its underwater UV launched an attack on the area via Mizarvision #OSINTpic.twitter.com/k1DLtOcloL
For its part, the Russian Ministry of Defense had unsurprisingly denied that any damage was inflicted on the submarine or to any personnel at the port. The ministry has released a video that it claims shows the undamaged boat, but does not offer a view of the stern end. The background is also heavily censored. Even so, it does still reveal what looks like piles of broken concrete debris left on the pier after the explosion, which was clearly visible in the SBU’s video of the attack, as well as in the satellite imagery available now.
The press service of the Russian Black Sea Fleet, which operates the submarine, also denies any damage to its vessels. This is also consistent with reports from various Russian naval monitoring channels on social media, but clear corroborating evidence has yet to emerge.
Overall, at this stage, we still cannot say with any authority what degree of damage, if any, the submarine may have actually sustained.
On the other hand, the attack does show Ukraine was at least able to slip a UUV into a heavily defended harbor, in daylight, and detonate its warhead only a few dozen or so feet away from a prized Russian submarine worth, according to the SBU, around $400 million.
With that in mind, Russia is likely to introduce new countermeasures against this particular mode of attack, one which Ukraine has spent some time developing.
The results of yesterday’s attack, while inconclusive for now, will likely spur further such developments in Ukraine, as well. Before SBU targeted the submarine in Novorossiysk, Ukraine had unveiled a UUV dubbed Marichka, designed to launch kamikaze attacks against ships and maritime infrastructure. At least one other Ukrainian UUV, known as Toloka, has previously been disclosed. It’s unclear if either of these has any relationship to the Sub Sea Baby.
Video of the Toloka UUV:
Автономний підводний дрон TOLOKA
Furthermore, the attack confirms that the Black Sea Fleet is very much still a prime target for Ukraine. This applies especially to the submarines like the Project 636 types and corvettes that are able to launch Kalibr long-range cruise missiles. These weapons have been regularly used in Russia’s nightly barrages launched against targets across Ukraine.
Already, Ukrainian naval actions had forced the Black Sea Fleet to retreat from bases on the occupied Crimean Peninsula to Novorossiysk. Attacks in Crimea were also prosecuted against another Improved Kilo class submarine. In September 2023, the Rostov-on-Don was severely damaged during a combined missile and USV attack on Sevastopol. Ukraine later claimed it was destroyed.
Photo showing damage to the Improved Kilo class submarine at Sevastopol, apparently first published by the Conflict Intelligence Team. CIT via X
At the start of Russia’s full-scale invasion of Ukraine, the Black Sea Fleet had a total of six Project 636 submarines available.
Other navies around the world will likely have watched yesterday’s attack with interest.
As well as the United States, China and many other nations are developing their own UUVs for missions like this one.
UUVs are able to attack vessels and other targets at long distances and can be launched from submarines and motherships, further extending their range. They can also be used for surveillance and mine laying, among other duties. You can read more about these vessels in various TWZ stories here.
Ultimately, whether or not the Russian submarine was damaged, the attack has demonstrated once again that the war in Ukraine is a crucible for the development of new military technologies, especially uncrewed ones.
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Ukraine’s state security service (SBU) said it carried out the first-ever uncrewed underwater vehicle (UUV) attack on a Russian vessel. The strike was on a Project 636 Varshavyanka class, orImproved Kilo class diesel-electric submarine, in the Black Sea naval stronghold of Novorossiysk. It would mark a historic first successful use of a UUV as an anti-ship attack weapon.
The SBU released a video it says shows the submarine docked at Novorossiysk along with several other ships. The video pans from right to left and at about the 16-second mark, the submarine erupts in an explosion. That means the UUV, which is not visible in the video, was able to navigate a packed harbor to strike a specific vessel. While we cannot independently verify the SBU claim about the use of a UUV in the strike, they did confirm that assertion to us directly.
Russia, meanwhile, denies any damage was caused by the attack.
‘The information disseminated by special services of Ukraine about the alleged ‘destruction’ of one of the Russian submarines in the bay of the Black Sea Fleet’s Novorossiysk naval base does not correspond to reality,” the Russian Defense Ministry (MoD) claimed on Telegram. “Not a single ship or submarine as well as the crews of the Black Sea Fleet stationed in the bay of the Novorossiysk naval base were damaged as a result of the sabotage. The watercraft serve normally.”
Today’s UUV attack appears to be the culmination of Ukraine’s development of these weapons and once again shows that the war-torn country is at the forefront of modern drone warfare innovation. Little is known about the Sub Sea Baby UUV, not to be confused with the highly adaptable Sea Baby uncrewed surface vessels (USVs) that have wreaked havoc on the Russian Navy.
Russian Defense Ministry announced that Ukraine attempted to attack the Ivan Khurs signals intelligence ship of the Russian Navy with 3 unmanned surface vessels (USVs) in the Black Sea this morning.
Moscow released footage allegedly showing the destruction of one of the USVs. pic.twitter.com/YfS7xWSGWw
— Status-6 (Military & Conflict News) (@Archer83Able) May 24, 2023
The U.S., China and many other nations are developing their own UUVs for missions like the one that struck the Improved Kilo class submarines. UUVs can provide the ability to strike vessels and other targets at long distances and can be launched from submarines and motherships, extending their range. They can also be used for reconnaissance and mine laying, among other duties. You can read more about these vessels in our catalogue of stories here.
In the case of the Improved Kilo class boat, “the vessel suffered critical damage and was effectively put out of action,” the SBU claimed. “On board the submarine were four launchers for ‘Kalibr’ cruise missiles, which the enemy uses to strike at the territory of Ukraine.”
The Russian Navy Improved Kilo class submarine Rostov-on-Don transited the Bosphorus Strait en route to the Black Sea on February 13, 2022 in Istanbul, Turkey (Photo by Burak Kara/Getty Images) BURAK KARA
The submarine damaged by the Sea Baby UUVs is one of six Improved Kilo class boats that were operated by the Russian Black Sea Fleet, a retired Russian Navy officer who uses the @Capt_Navy X handle told The War Zone.
These submarines are quite capable and can be very hard to detect when dived and running on battery power. These submarines carry Kalibr long-range cruise missiles that have frequently been used to attack Ukraine.
The Sub Sea Baby UUV attack “was a joint operation of the 13th Main Directorate of Military Counterintelligence of the SBU and the Naval Forces of Ukraine,” SBU explained, adding that the estimated cost of one of the Russian submarines is about $400 million.
Ukraine says it struck a Russian submarine with an uncrewed underwater vehicle (UUV) in Novorossyisk, Russia. (Google Earth)
This incident also marks the second time an Improved Kilo class submarine in Crimea was attacked by Ukraine. In September 2023, the Rostov-on-Don was severely damaged during a combined missile and uncrewed surface vessel (USV) attack on Sevastopol. Ukraine later claimed it was destroyed. You can see the damage to that submarine below.
One of two photos of the damage to the Improved Kilo class submarine apparently first published by the Conflict Intelligence Team. CIT via X A picture showing damage to a Kilo class submarine following a Ukrainian cruise missile strike on Sevastopol in September 2023. CIT via X
If today’s attack did damage the submarine significantly, Russia would be left with four examples operating as part of the Black Sea Fleet.
While much about the Sub Sea Baby UUVs remains a mystery, a proven ability to use them as weapons holds Russian vessels at even greater risk. Novorossiysk was seen as something as a relative safe haven for the Black Sea Fleet, although aerial and sea drone attacks have occurred there. But the idea that Ukraine can use underwater drones to strike ships in port there changes this calculus, if that is indeed the true method of the attack. As a result, we will also be seeing a change in Russia’s defensive posture at the sprawling port located on the northeastern edge of the Black Sea.
At the same time, if this attack was executed by a UUV, it would be another world first and is likely a harbinger of things to come. Hitting ships in port over great distances via underwater drone attack is an asymmetric capability. It’s also one that America’s adversaries are investing in heavily, and especially China.
With all this in mind, the attack on the submarine serves as another reminder that the war in Ukraine has become a conflict where theory and development are put into practice.
