North Korea claims it has built nuclear attack submarine to counter US Navy

On September 8, North Korea said it had christened a purported nuclear attack submarine it has been developing for years, a step leader Kim Jong Un described as crucial in his efforts to build a nuclear-armed navy to counter the United States and its Asian allies.

"A new powerful entity has emerged to demonstrate the rapid development of the Juche-based naval force all over the world ... The submarine-launching ceremony heralded the beginning of a new chapter for bolstering up the naval force of the DPRK [Democratic People's Republic of Korea] and made clearer the steadfast will of the WPK and the government of the DPRK to further strengthen the state nuclear deterrence," state-run Korean Central News Agency (KCNA) reported on September 8.

"The ceremony was splendidly held on 6 September in the presence of Kim Jong-un ... with attendance of leading officials of the party, government and military," the report added.

Kim Jong-un conferred the transfer certificate on the commander of the submarine squadron under the East Sea Fleet of the Navy.

Named "Hero Kim Kun Ok", the attack submarine will perform its combat mission as one of the core underwater offensive means of the naval force of the DPRK. The submarine was unveiled ahead of the country marking 75 years of its founding on 9 September.

Meanwhile, South Korean officials were sceptical that the submarine would work as North Korea described and said it likely wasn’t ready for operational duty. Still, the vessel’s development underscored how the North continues to potentially extend the range of its nuclear arsenal with systems that are harder to defect in advance.

 A South Korean official at the Joint Chiefs of Staff said that "an analysis of the external features of the North Korean submarine so far shows that parts of it have been enlarged to carry a missile".

Based on Kim Jong Un’s comments and photos by North Korean state media, it’s likely the submarine is the same one Kim inspected in 2019 while it was under construction, which experts then assessed as an effort to convert an existing Romeo-class submarine. The submarine appears to have at least 10 launch tubes – four of them apparently larger than the other six – that are possibly designed for missiles.

North Korea previously had been testing a variety of missiles designed to be fired from submarines as it pursued the ability to conduct nuclear strikes from underwater, which in theory would bolster its deterrent by ensuring a survivable capability to retaliate after absorbing a nuclear attack on land.

Ballistic missile submarines would also add a maritime threat to the North’s growing collection of solid-fuel weapons fired from land vehicles that are designed to overwhelm missile defences in South Korea and Japan.

Still, it would take considerable time, resources and technological improvements for the heavily sanctioned nation to build a fleet of at least several submarines that could travel quietly and reliably execute attacks, analysts say.