US-South Korea nuclear submarine deal: What does it mean?

South Korea’s authorities has introduced that it has finalised an settlement to construct nuclear-powered submarines in partnership with america.

The US has permitted the “assault submarines” and agreed to cooperate in sourcing gasoline, in keeping with a reality sheet launched by the White Home on Thursday.

The settlement marks a major step in South Korea’s relations with the US and comes amid a interval of rising tensions on the Korean Peninsula: with the nuclear-armed North Korea, and an expansionist China to the west.

This is what it’s good to know concerning the settlement.

The settlement between the US and South Korea comes as leaders from each international locations reached a broad commerce deal earlier final month that might see reciprocal tariffs reduce to fifteen% from 25%.

US President Donald Trump had slapped a tariff price on Seoul of 25% earlier this 12 months – which his counterpart Lee Jae Myung managed to barter down to fifteen%, after Seoul mentioned it might make investments $350bn (£265bn) within the US, together with $200bn in money funding and $150bn in shipbuilding.

In a White Home readout launched on Thursday, the US mentioned it had “given approval for the Republic of Korea to construct nuclear-powered assault submarines… [and would] work intently to advance necessities for this venture, together with avenues to supply gasoline”.

In an earlier put up on his social media platform Fact Social, Trump had mentioned the vessels can be constructed at a shipyard in Philadelphia run by South Korean conglomerate Hanwha.

Solely six international locations at the moment possess nuclear-powered strategic submarines: the US, China, Russia, the UK, France and India.

South Korea already possesses about 20 submarines, however they’re all diesel propelled and due to this fact have to floor much more steadily. Nuclear submarines are additionally capable of function additional and quicker.

“I’ve given them approval to construct a nuclear-powered submarine, relatively than the old school, and much much less nimble, diesel-powered submarines that they’ve now,” Trump wrote on Fact Social.

South Korea is a powerhouse in terms of civilian nuclear power. It had a nuclear weapons programme within the Seventies however gave it up following US stress.

And so its capacity to counterpoint or reprocess uranium is restricted by the US as it’s fully depending on imports.

The most recent vessel programme is geared toward countering North Korea, which not too long ago revealed that it was pursuing its personal nuclear submarine programme.

President Lee had informed Trump on the APEC summit final month that South Korea wanted them for that categorical objective.

In a TV interview final week, Ahn Gyu-back, South Korea’s Minister of Defence, mentioned that nuclear submarines can be a “proud achievement” for South Korea, and a serious leap in strengthening the nation’s defence in opposition to the North.

The stealth of nuclear submarines would hold North Korean chief Kim Jong Un “awake at night time”, he added.

North Korea has additionally been pursuing a nuclear submarine programme – probably with Russia’s assist, in keeping with South Korean officers.

In March 2025, North Korea unveiled footage of what it claimed was a nuclear-powered submarine that was beneath building, exhibiting Kim visiting the shipyard.

Pyongyang is anticipated to have the submarines inside the subsequent few years.

North Korea can be estimated to have an arsenal of roughly 50 nuclear weapons, as a part of its broader nuclear weapons programme.

Jo Bee-yun, a analysis fellow on the Sejong Institute, prompt that Seoul’s acquisition of nuclear submarines will assist it keep apace in East Asia’s escalating arms race.

“North Korea’s nuclear weapon is a longtime reality,” she informed the BBC. “[South Korea acquiring] nuclear submarines is barely a step within the bigger development of rising rigidity.”

It’s unclear how a lot the nuclear-propelled submarines will contribute to South Korea’s defence capabilities – and although they’re very costly, they do not fairly change the stability of energy on the Korean Peninsula, in keeping with some specialists.

Yang Uk, a analysis fellow on the Asan Institute for Coverage Research, informed the BBC that the nuclear subs’ major objective is to guarantee South Korean voters that their authorities is responding to North Korea’s nuclear menace.

“South Korea can’t develop its personal nuclear weapons to counter North Korea’s,” Dr Yang mentioned. “What’s one thing that they’ll do? Fielding nuclear submarines.”

Dr Yang believes North Korea may revel within the change, nonetheless, as a result of it reinforces their justification to carry on to nuclear weapons – that means it’s going to change into harder to demand that Pyongyang quit its nuclear arsenal.

Jo nonetheless emphasised the strategic benefit that South Korea stands to achieve from the brand new submarine deal, describing it as a “main change” which “means South Korea is now a regional participant”.

“The very best characteristic of a nuclear submarine is its pace,” she mentioned. “It might now go quick and much and South Korea can function along with extra international locations.”

For Washington, help for South Korea’s nuclear-powered submarine programme doubtless goals to place stress on each North Korea and China.

“Trump has put the burden of defence spending on the again of South Korea,” Dr Yang defined. “South Korea will drastically develop its defence price range. They may act as America’s proxy in placing stress on China and North Korea.”

US and China have lengthy competed for strategic affect in South Korea, leaving Seoul to stroll a geopolitical tightrope. Extra not too long ago, China has been growing its naval exercise close to South Korea’s maritime border – a transfer akin to these seen within the South China Sea.

Beijing should be “livid” about South Korea’s nuclear submarine settlement with the US, Dr Yang mentioned.

Following the deal’s announcement, the Chinese language Ambassador to South Korea, Dai Bing, mentioned he hoped South Korea would “cope with this challenge prudently, taking into account the issues of all sides”.

Dai additionally added that Beijing was participating with Seoul on the matter by means of diplomatic channels, and emphasised that “the (safety) scenario on the Korean Peninsula and within the area remains to be advanced and delicate”.

Though President Trump mentioned the submarines can be in-built Philadelphia and produce jobs to the US, South Korean officers have maintained they should be constructed domestically, the place present amenities can ship them in a a lot shorter timeline.

South Korea’s Prime Minister Kim Min-seok had himself mentioned throughout a parliamentary listening to that the South Korean owned shipyard in Philadelphia did “not have the potential” to construct such vessels, in keeping with reviews.

Hanwha, who owns the shipyard, has but to touch upon the matter.

However now that an settlement has been reached, the subsequent step is to regulate the nuclear settlement between the 2 international locations, permitting for the US to offer nuclear gasoline and to set the fence for its navy use.