North Korea's nuclear arsenal: Russian tech bolsters threat

The treaty on "comprehensive strategic partnership" concluded between Moscow and Pyongyang creates a formal framework for military cooperation, which both regimes have been developing for many months.

According to new reports, munitions, weapons, and pilots and soldiers handed over by Kim Jong Un to Putin form a type of currency in their bilateral relations. The ruler of North Korea aims to acquire technologies that—despite many years of attempts—he has not been able to provide for his army through his own defence sector forces.

In an interview with "The Economist," Kyrylo Budanov, head of Ukraine's military intelligence, claims, citing intelligence data, that North Korea has received or will receive from Russia the technology to produce low-yield tactical nuclear weapons. This will be complemented by solutions allowing for the launch of ballistic missiles from submerged submarines.

This signifies the end of the shaky balance in relations between the North and the South, maintained for decades on the Korean Peninsula.

North Korea announced possession of nuclear weapons in 2005. However, the problem for Pyongyang is that North Korean warheads are large and require equally large ballistic missiles for transport (the smallest of which is probably the tactical Toksa KN-02 missile).

These – in theory – can be destroyed in flight, and South Korea has not spared any effort for years to identify and, in the event of a conflict, quickly destroy North Korean nuclear installations, including mobile ballistic missile launchers.

Pyongyang's acquisition of the capability to build small, lightweight warheads means artillery can now carry them. Although this solution was abandoned worldwide decades ago, in the event of a conflict on the Korean Peninsula, nuclear artillery might be an ace in Kim's sleeve.

Especially since his army is equipped with, among other things, M-1978 Koksan 170 mm howitzers. This weapon has a range of even 60 kilometres, meaning that from North Korean territory, it can target Seoul and more.

The large number of howitzers and their potential dispersion makes it nearly impossible to destroy them all in a short time, just as it is to neutralise a large number of incoming artillery shells simultaneously. In the event of a conflict with the North, this would put South Korea in a difficult position, exposing part of the country, including its capital, to nuclear strikes.

Equally important to Kim Jong Un is the capability to launch ballistic missiles from submarines. North Korea is, in terms of the number of submarines, a true powerhouse. According to varying estimates, Pyongyang has 60-80 submarines – more than Russia, China, or the United States.

The backbone of the underwater fleet has been the Sang-O class submarines, built since the 1990s. These are small (but not miniature) vessels, slightly smaller than the Kobben class submarines operated by Poland until recently.

Korean vessels are 34 metres long, displace 414 tonnes underwater, and are operated by a 15-person crew. They are equipped with a radar and four 533 mm torpedo tubes. North Korea has built at least 41 of these units, one of which was captured by South Korea.

Pyongyang also operates 20 imported Romeo class submarines from China (displacement of 2,015 tonnes, length of 74 metres), as well as a significant number of miniature vessels. Although these are technologically outdated, they can pose a serious threat, cutting South Korea off from aid delivered by sea in the event of a war.

North Korea's underwater fleet capabilities were demonstrated in 2010, when in the vicinity of Baengnyeong Island in the Yellow Sea, a South Korean corvette was sunk due to a mysterious explosion. The investigation found that the South Korean warship was sunk by a torpedo fired by an undetected, unidentified Northern submarine.

Among conventional units, the likely sole (at least two are under construction) North Korean carrier of ballistic missiles stands out. It is the Sinpo-C/Gorae class submarine, introduced into service in 2023, a modification of the Romeo class.

This carrier has been home to Pukguksong-3 ballistic missiles, produced since 2017, whose launchers (probably three) are located in the submarine's sail. Although North Korea has already conducted successful underwater missile launches – both using the vessel and underwater test installations – it likely encountered problems blocking the development of these capabilities.

Support from Russia solves this problem, concurrently giving Kim another card – the ability to place nuclear warheads not only on land but also at sea. For South Korea, this is very bad news.