US-South Korea Partnership: Nuclear Submarines and Strategic Significance

Sun Nov 16 2025 03:15:30 GMT+0200 (Eastern European Standard Time)

The collaboration between the US and South Korea to develop nuclear-powered submarines signifies a new phase in defense. Amidst rising tensions with North Korea and China, this agreement aims to fortify South Korea's military capabilities.

The United States and South Korea have finalized an agreement to build nuclear-powered submarines, a strategic move to enhance South Korea's defense against North Korea's growing military threats. This partnership underscores deepening military ties and reflects both nations' responses to regional security concerns, particularly amid North Korea's nuclear ambitions and China's assertiveness. With the potential construction set to occur in South Korea, the deal marks a significant turn in East Asian military dynamics.

South Korea's government has announced that it has finalized an agreement to build nuclear-powered submarines in partnership with the United States.

The US has approved the 'attack submarines' and agreed to cooperate in sourcing fuel, according to a fact sheet released by the White House on Thursday.

This agreement marks a significant step in South Korea's relations with the US and comes amid a period of growing tensions on the Korean Peninsula, with the nuclear-armed North Korea and an expansionist China to the west.

What's in the agreement?

The agreement between the US and South Korea comes as leaders from both countries reached a broad trade deal earlier last month that would see reciprocal tariffs cut to 15% from 25%. US President Donald Trump had slapped a tariff rate on Seoul of 25% earlier this year, which his counterpart Lee Jae Myung managed to negotiate down to 15% after Seoul said it would invest $350bn (£265bn) in the US, including $200bn in cash investment and $150bn in shipbuilding.

In a White House readout released on Thursday, the US stated it had 'given approval for the Republic of Korea to build nuclear-powered attack submarines... [and would] work closely to advance requirements for this project, including avenues to source fuel'.

Only six countries currently possess nuclear-powered strategic submarines: the US, China, Russia, the UK, France, and India.

South Korea possesses about 20 submarines, all diesel-propelled, which necessitate more frequent surfacing. Nuclear submarines will allow for extended operational capacities.

South Korea's Minister of Defence emphasized the need for these advanced vessels to counter North Korea’s emerging nuclear threats, with the stealth factor of nuclear submarines providing a considerable strategic advantage.

Does North Korea have nuclear submarines?

North Korea has been pursuing its own nuclear submarine program, recently claiming to build a nuclear-powered submarine.

Will this inflame tensions on the Korean Peninsula?

The introduction of nuclear submarines to South Korea’s naval capabilities raises questions on its impact on regional military dynamics. Some experts argue that while they won't significantly alter the balance of power, they serve to reassure South Koreans about their government's response to threats.

For the US, this support for South Korea's nuclear submarine program aims to exert pressure on both North Korea and China, reinforcing strategic partnerships in East Asia.

What next?

The agreement paves the way for further negotiations regarding nuclear fuel supply, critical for the submarines’ operation. South Korean officials are prioritizing local construction capabilities to ensure timely delivery and operational readiness.