[Current Affairs Show] Jung Sungjang: "High Likelihood North Korea Will Launch Nuclear-Powered Submarine Within Five Years"

Joint Construction of Highly Enriched Nuclear Submarines by South Korea and the US Is Not a Bad Option
The US Is Also Positive About Uranium Enrichment and Nuclear Fuel Reprocessing
Research on Nuclear-Powered Submarines Began During the Kim Youngsa

■ Broadcast: The Asia Business Daily "So Jongseop's Current Affairs Show" (Monday to Friday, 4-5 p.m.)

■ Host: Political Specialist So Jongseop ■ Director: Park Sumin, Producer

■ Guest: Jung Sungjang, Deputy Director of the Sejong Institute (November 3)

So Jongseop: Hello, everyone. Welcome to So Jongseop's Current Affairs Show. Today, we will be discussing nuclear-powered submarines-what they are, and the current situation in North Korea-with Jung Sungjang, Deputy Director of the Sejong Institute. Deputy Director Jung has long argued that South Korea needs to possess nuclear-powered submarines. I am curious about the reasons.

Jung Sungjang, Deputy Director of the Sejong Institute, is appearing on "So Jongseop's Current Affairs Show" and having a conversation with So Jongseop, a political specialist.

Jung Sungjang: In January 2021, North Korea expressed its intention to develop nuclear-powered submarines at the 8th Congress of the Workers' Party. This has shown rapid progress in 2023 and this year. In 2023, North Korea launched the Hero Kim Geunok, a diesel-powered submarine capable of carrying nuclear weapons. It does not appear to be fully operational yet. However, what poses an even greater threat to us is a nuclear-powered submarine capable of carrying nuclear weapons.

In March this year, North Korea revealed a submarine under construction, and it was surprisingly evaluated as having made significant progress. When North Korea announced its intention to develop a strategic nuclear submarine in 2021, many domestic and international experts scoffed at the idea, doubting North Korea's shipbuilding capabilities and dismissing the prospect of a nuclear-powered submarine as unrealistic. That is why, from that time, I argued that if North Korea were to build a strategic nuclear submarine, we must also prepare in earnest.

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So Jongseop: So your position is that we should respond to North Korea with "an eye for an eye"?

Jung Sungjang: Yes. If North Korea acquires a strategic nuclear submarine, it will have a clear second-strike capability. Land-based assets can be detected by satellites if North Korea attempts to attack South Korea or the US with missiles, making it possible to strike them preemptively. However, it is much harder to detect submarines underwater. If a North Korean submarine enters the South Sea and attacks with nuclear weapons, even THAAD cannot intercept it. A nuclear-armed submarine could cross the Pacific and approach the US mainland. If a strategic submarine attacks the US mainland, reentry technology is not even necessary.

So Jongseop: They could launch right from the coast.

If North Korea acquires the capability to strike the US mainland, it will be difficult for the US to maintain extended deterrence

Jung Sungjang: If North Korea gains this capability, the US will not be able to strike North Korea in a contingency. For example, if North Korea attacks South Korea with nuclear weapons or an EMP (electromagnetic pulse) bomb, the US would naturally have to retaliate against North Korea's nuclear weapons. However, if North Korea can reliably strike the US, the US will inevitably hesitate. In other words, would the US abandon New York to save Seoul? The answer is no. Elbridge Colby, the current US Deputy Assistant Secretary of Defense for Strategy and Force Development, made this very clear. He said, "The extended deterrence promised by the Biden administration in the past is a promise that cannot be kept. No president can accept the deaths of hundreds of thousands or millions of American citizens to protect South Korea." He was very blunt about it.

President Trump approved South Korea's construction of nuclear-powered submarines, increasing interest in subsequent negotiations.

So Jongseop: That could be the limit of extended deterrence.

Jung Sungjang: Extended deterrence would effectively collapse. In that case, we would have no way to respond to North Korea's nuclear threat, and North Korea could use its nuclear weapons for various purposes. The lowest level is as a threat. For example, the Northern Limit Line (NLL) in the West Sea is a thorn in North Korea's side. The NLL was drawn in 1953 by the UN Commander based on the international maritime law at the time, which recognized territorial waters up to 3 nautical miles. North Korea was told not to cross 3 nautical miles from its coastline, and that is how the NLL was established. North Korea has significant dissatisfaction with the NLL.

So Jongseop: They do not recognize it, right?

If not for the Russian deployment, North Korea would have taken action to neutralize the NLL

Jung Sungjang: North Korea's dissatisfaction began to erupt in the 1990s, when international maritime law changed. Territorial waters were extended to 12 nautical miles. North Korea demanded recognition of 12 nautical miles, but South Korea and the US refused and maintained the existing NLL. North Korea began to protest, claiming this was a violation of international law, and naval skirmishes in the West Sea began. The dispute over 3 or 12 nautical miles is closely tied to economic interests.

At the end of 2023, North Korea announced a hostile two-state policy and declared its intention to neutralize the NLL. In January 2024, at the Supreme People's Assembly, they reiterated their intent to neutralize it. If not for North Korea's deployment to Russia, North Korea would have taken steps to neutralize the NLL in 2024 or 2025.

So Jongseop: You mean they would have used force?

Jung Sungjang: Yes. By sending troops to war, North Korea had to pay a significant price and learn many lessons, so it could not afford to start two wars. However, once the Russia-Ukraine war ends, North Korea will turn its attention back to this issue. If North Korea occupies Baengnyeong Island and South Korea retaliates, North Korea could threaten to use nuclear weapons on Seoul. We would then be forced to agonize over whether to retaliate or not. This can be used as a means to restrain our actions.

The second possible scenario is not using nuclear weapons for mass destruction, but as an EMP (electromagnetic pulse) bomb, as North Korea claimed during its sixth nuclear test. If detonated at high altitude, say over Daejeon, about one-third of our territory-central South Korea and beyond-would experience a blackout in electrical communications. This would cause enormous economic damage, force many foreign companies to withdraw, and it could take six months or a year to recover. Such chaos would be devastating.

High likelihood North Korea will launch a nuclear-powered submarine within five years

So Jongseop: How far has North Korea's nuclear-powered submarine development progressed?

Jung Sungjang: In March this year, North Korea unveiled the hull of a nuclear submarine. It must be equipped with a small reactor. North Korea cannot build such a reactor on its own, but if Russia provides it, the situation changes. Based on the hull that was revealed, I believe there is a high likelihood North Korea will launch a nuclear submarine within the next five years.

So Jongseop: Five years? Isn't that quite fast?

North Korean State Affairs Commission Chairman Kim Jong Un attending the expanded meeting of the 12th plenary session of the 8th Central Committee of the Workers' Party held from June 21 to 23. Photo by Yonhap News Agency

Jung Sungjang: That's right. Judging by the nuclear-powered submarine North Korea revealed this year, it is making significant progress. Many experts mistakenly believe that Russia would never provide North Korea with advanced nuclear submarine technology, but there is no basis for that assumption. In the past, when India developed nuclear submarines, Russia lent them an old nuclear submarine. North Korea, having sent troops to the Ukraine war and suffered many casualties, will expect compensation from Russia.

Also, it is not widely known, but when North Korea withdrew from the NPT in the early 1990s, President Kim Youngsam decided that South Korea should at least build nuclear-powered submarines. That was the beginning, but at that time, South Korea did not have the technology to build submarines, so research began. We paid Russia to learn reactor technology for submarines at that time.

So Jongseop: During the Kim Youngsam administration?

South Korea paid Russia to learn small reactor technology during the Kim Youngsam administration

Jung Sungjang: Yes. Russia borrowed a lot of money from South Korea during the Roh Tae-woo administration and, unable to repay, provided South Korea with considerable defense technology, though not nuclear submarine technology. We paid separately to learn small reactor technology, which now contributes to South Korea's nuclear power industry.

So Jongseop: Why do you think the US approved the construction of nuclear-powered submarines at this time?

Jung Sungjang: The US naturally prefers cooperation with South Korea, which has twice the shipbuilding capacity of Japan. President Trump believes cooperation with South Korea is absolutely necessary to prevent China from surpassing the US in naval power. If the US can deploy only three nuclear submarines to the Western Pacific in a contingency, but South Korea and Japan also have nuclear submarines, the burden on the US would be reduced.

On December 17, 2023, the US nuclear-powered submarine USS Missouri (SSN-780) docked at Busan Naval Base. Photo by Yonhap News Agency

So Jongseop: If Japan or Taiwan also decide to build nuclear submarines, wouldn't nuclear submarine competition intensify in Northeast Asia?

Jung Sungjang: We do not need to view this entirely negatively. I do not think Taiwan has the capability to develop them, and it would actually benefit us if Japan acquires nuclear submarines. North Korea will not stop at building just one nuclear submarine; it will continue to build more. If both South Korea and Japan possess nuclear submarines, we can more effectively deter North Korea. North Korea is already making it possible to launch nuclear weapons from its existing medium-sized submarines.

Those weapons are a real threat to us. We need to monitor them, but diesel submarines may not be able to keep up or track them, which is a threat not only to South Korea but also to Japan. Therefore, joint production would reduce our burden. Although we cannot load nuclear weapons on our nuclear-powered submarines, at the very least, we could track North Korea's nuclear-powered submarines and intercept them if necessary. We must at least have the capability to contain North Korea's nuclear submarines.

Jointly building highly enriched nuclear-powered submarines with the US is not a bad idea

So Jongseop: President Trump recently mentioned building nuclear-powered submarines at the Phili Shipyard in the US. What are your thoughts?

Jung Sungjang: South Korea and the US have agreed to establish a Shipbuilding Cooperation Committee. Previously, under the Biden administration, former President Yoon Sukyeol and the US created the Nuclear Consultative Group (NCG). Similarly, the Shipbuilding Cooperation Committee will institutionalize shipbuilding cooperation, and there will be negotiations and bargaining. President Trump's main interest is job creation, so he brought up the Phili Shipyard, but it does not have facilities to build nuclear submarines. We need to find a compromise between US and South Korean demands.

We need to consider various options. Currently, South Korea plans to use low-enriched uranium as fuel for nuclear-powered submarines, which would require dismantling the submarine and replacing the reactor every 10 years. However, if we use highly enriched uranium as the US does, the fuel can last for about 30 years. That is not a bad option. If we build them in the US, we may have to transfer facilities and personnel, and US labor costs and cultural differences would double the cost and time required. It could take twice as long and cost twice as much. However, if South Korea and the US jointly build US-style nuclear-powered submarines, that would not be a bad option.

One could be built in the US and one in South Korea. We could also build several simultaneously and supply nuclear-powered submarines to Australia, as the US plans. There are various ways to cooperate, and joint construction of nuclear-powered submarines is one of them. That way, both countries could share the benefits.

Hanwha Phili Shipyard located in Philadelphia, Pennsylvania, USA. Yonhap News Agency

So Jongseop: How long would it take? Many expect it to take close to 10 years...

Jung Sungjang: That sounds about right. This is a long-term project, and it will take at least six months to a year to reach a concrete agreement through negotiations between South Korea and the US. Building two submarines simultaneously in the US and South Korea is, in my view, the most reasonable approach. The US is demanding an increase in defense cost sharing, so if we are to increase our contributions, this is an opportunity to acquire nuclear-powered submarines, which we will eventually need anyway. In a way, this allows us to meet US demands while also serving our own interests through nuclear-powered submarines.

So Jongseop: Do you think the US will relax restrictions on uranium enrichment and spent nuclear fuel reprocessing?

Agreement on uranium enrichment and spent nuclear fuel reprocessing likely within a year

Jung Sungjang: I believe it is possible. Although it is regrettable that this was not agreed upon at the recent South Korea-US summit, I understand that our government officials have received the US's principled agreement in meetings so far. Therefore, I expect an agreement soon. President Trump is a businessman, so he is keeping this card in reserve to extract further concessions in tariff or other negotiations. He is holding onto this as a bargaining chip for further concessions in various negotiations with South Korea.

If South Korea-US cooperation progresses further, South Korea could use this as leverage to import more from the US. Since US officials are currently positive, I expect an agreement within six months to a year, followed by detailed working-level negotiations. Government-to-government negotiations will not be concluded quickly, so at least a year should be expected.

So Jongseop: There are concerns in the US that issues like nuclear-powered submarines, uranium enrichment, and spent fuel reprocessing could be linked to nuclear weapons development.

Jung Sungjang: The Lee Jaemyung administration is firmly opposed to nuclear armament. I believe this will remain the case. However, the issues of enrichment and reprocessing are being approached from economic and environmental perspectives. South Korea is the world's fifth or sixth largest nuclear power nation. Among such nuclear powerhouses, there are none without reprocessing and enrichment capabilities. If we do not acquire reprocessing capabilities, our spent nuclear fuel will reach capacity around 2030, and without storage facilities, we may have to shut down nuclear power plants. Therefore, securing reprocessing capabilities is urgent.

Currently, about 30% of our enriched uranium is imported from Russia, but the US and Europe are moving to reduce imports from Russia. We have no choice but to follow that direction. Therefore, we need enrichment capabilities. Our goal is to have enrichment and reprocessing capabilities equivalent to Japan's. This is about economic security, environmental and energy security, and, secondarily, securing our nuclear potential. If Japan decides, it can arm itself with nuclear weapons within three to six months, so it is called a potential nuclear power. If we acquire enrichment and reprocessing capabilities, we also become a potential nuclear power, and North Korea will find it harder to threaten us as easily as it does now. If North Korea continues to threaten us, we could also consider nuclear armament, which would be a source of concern for North Korea. In this sense, it could serve as a factor that reduces North Korea's threats.