North Korea’s Navy Shifts From Coastal Guard to Open‑Sea Threat

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Video originally published on June 30, 2025.

For decades the Democratic People’s Republic of Korea’s navy has been dismissed as a relic of Cold‑War era coastal defense—an aging flotilla of Soviet‑style frigates, Chinese‑built submarines and a swarm of obsolete patrol craft. Recent developments, however, reveal a rapid transformation. New destroyers equipped with vertical launch systems, a nuclear‑powered submarine and a flurry of Russian‑sourced technology signal a strategic pivot that could reshape maritime security across the Yellow Sea and beyond.

Key Takeaways

For decades the Democratic People’s Republic of Korea’s navy has been dismissed as a relic of Cold‑War era coastal defense—an aging flotilla of Soviet‑style frigates, Chinese‑built submarines and a swarm of obsolete patrol craft.
Historically the DPRK’s naval force has been defined by its antiquated hardware.
The most visible symbols of the navy’s modernization are the Choe Hyon‑class destroyers.
The shift in naval capability aligns with several strategic imperatives articulated in the source material.
The emergence of a blue‑water capable DPRK navy reshapes the maritime security calculus in the region.
The article is grounded strictly in the source video script and listed references.

From Riverine Flotilla to Blue‑Water Aspirations

Historically the DPRK’s naval force has been defined by its antiquated hardware. The backbone of the fleet consists of two Najin‑class frigates launched in the 1970s and roughly twenty Romeo‑class submarines acquired from China in the mid‑1970s and later produced domestically until 1995. Most vessels operate within a 50‑kilometre radius of the Korean coastline, and the majority of the reported 780 ships are small patrol boats and fast‑attack craft that are “decades past their prime and barely seaworthy.” This composition reinforced a defensive posture focused on deterring a land‑based invasion rather than projecting power at sea. The narrative began to shift late last year when North Korea unveiled a newly constructed warship at the Nampo Shipyard. Described as a destroyer with vertical launch systems and phased‑array radar, the vessel represented a stark departure from the “Stalin‑aged tankers” that had previously populated Pyongyang’s harbors. The appearance of such a platform suggests an ambition to move beyond coastal defense toward a capability that can operate on international maritime routes. With much of its vessels dating back to mid-20th century designs from the Soviets and Chinese, the fleet is dominated by just two aging Najin-class frigates from the 1970s—nearly fifty-year-old hulls that are not exactly going to be winning any wars—alongside about 20 Romeo-class submarines acquired from China in the mid-1970s and then produced domestically until 1995. Despite this, operating an aging fleet hasn’t caused much of an issue for Pyongyang over the last several decades, for the simple reason that their naval escapades have been minimal. GOV.UK - https://stratcommand.blog.gov.uk/2021/04/26/getting-to-grips-with-grey-zone-conflict/ China Strategic Risks Institute - https://www.csri.global/research/testing-the-waters France 24 - https://www.france24.com/en/live-news/20250114-nato-baltic-leaders-set-to-boost-security-after-cable-sabotage BBC News - https://www.bbc.co.uk/news/articles/cwy3zy9jvd4o Just Security - https://www.justsecurity.org/113221/chinas-shadow-fleet-war-on-taiwans-undersea-cables/ UK Parliament - https://commonslibrary.parliament.uk/seabed-warfare-protecting-the-uks-undersea-infrastructure/ Sky News - https://news.sky.com/story/uk-and-allies-to-use-ai-to-protect-undersea-cables-from-russian-shadow-fleet-attacks-13284632#:~:text=Pic:%20PA-,The%20Ministry%20of%20Defence%20said%20the%20UK%2Dled%20%22reaction%20system,transporting%20embargoed%20Russian%20oil%20products. Although estimates vary, several sources place the size of China’s fleet at between 300 and 600 vessels, while Russia’s shadow fleet is frequently reported to number around 600. But what is more concerning than international trade is the ability to launch missiles from this retrofitted naval force—an absolute game changer in case of sustained conflict.

New Platforms and Weapon Systems: Submarines, Missile‑Cruisers, and Asymmetric Tools

The most visible symbols of the navy’s modernization are the Choe Hyon‑class destroyers. The first of these 5,000‑ton ships entered service in April 2025, completing construction in just 400 days—roughly a quarter of the time the United States typically spends on destroyer builds. The class incorporates vertical missile launchers, a four‑faced phased‑array radar comparable to that on Russia’s Karakurt‑class warships, and an integrated air‑defense suite that mirrors Russia’s Pantsir system. In parallel, Kim Jong‑Un was photographed standing beside a newly built nuclear‑powered submarine, a leap from the diesel‑powered Romeo‑class fleet. The submarine is reported to be capable of launching submarine‑launched ballistic missiles (SLBMs), granting the DPRK a sea‑based nuclear strike option. Even the rollout of the second destroyer, despite a botched launch that caused the hull to capsize, was quickly remedied—North Korean officials claim the vessel has been “fixed” and righted within weeks. The rapid repair timeline underscores a new emphasis on survivability and sustained operational readiness. Collectively, these platforms expand the navy’s strike range, introduce sea‑based missile launch capability, and provide a survivable second‑strike option that was previously limited to land‑based systems. These new Choe Hyon-class destroyers are capable of projecting North Korean strength and influence throughout international maritime routes—which could cause a logistical nightmare for South Korea, Japan, and the United States. The four-faced phased array radar mounted on the Choe Hyon is similar in layout and installation angle to the radar systems deployed on Russia’s Karakurt-class warships. The first Choe Hyon-class destroyer was launched in April 2025 and was in operation conducting weapons tests within days. This is roughly a quarter of the time the US has been taking to build destroyers—although the American ships have (ironic) slightly more technology integrated into their construction. Far more concerning than questionable missile defense systems, though, is the lightning-fast progress Pyongyang has made on these vessels. Up until this point, the DPRK’s missile program has been limited to land-based launch systems. Kim Jong Un did, after all, earn himself the nickname of “Little Rocket Man.” But there’s one part of the North Korean military that almost nobody outside of the experts pays attention to: the Navy.

Strategic Calculus: Why Kim Jong‑Un Is Investing in a Dangerous Navy

The shift in naval capability aligns with several strategic imperatives articulated in the source material. First, sea‑based missile systems are “more elusive and mobile,” complicating detection and pre‑emptive targeting compared with fixed or even mobile land launchers. By embedding nuclear warheads on submarines and destroyers, Pyongyang can conceal its arsenal and retain the ability to retaliate even after a hypothetical pre‑emptive strike—what analysts term “survivable second‑strike capability.” Second, the new destroyers can “project North Korean strength and influence throughout international maritime routes,” threatening the logistical arteries that sustain South Korea, Japan and United States forces. The ability to launch missiles from these vessels would constitute “an absolute game changer in case of sustained conflict.” Third, the rapid development timeline—400 days for the first destroyer and weeks to repair the capsized second hull—suggests a systematic overhaul rather than ad‑hoc upgrades. The source notes that this pace is “unprecedented for North Korea’s naval capabilities and, we have to be honest, impressive even for global standards." Finally, the article links these advances to Russian assistance. Russian officials have reportedly helped upgrade missile guidance and targeting systems, donated a Pantsir‑S1 air‑defense system, and provided sophisticated electronic‑warfare equipment. The similarity of the Choe Hyon’s radar and air‑defense suite to Russian designs indicates a transfer of technology that accelerates the DPRK’s naval modernization. Together, these factors explain why Kim Jong‑Un is prioritizing a modern navy: to secure a credible deterrent, to enhance regional leverage, and to cement a partnership with Moscow that offsets the impact of international sanctions. What’s more is that this would provide North Korea with what’s called “survivable second-strike capability.” For those unfamiliar, this means that in the event of a preemptive attack that successfully eliminated all the DPRK’s land-based missile sites, they would still be able to retaliate with devastating effect. The construction of such a vessel in and of itself should raise concerns that Pyongyang has begun to move away from its historic naval strategy of focusing on coastal defense in case of a land-based invasion, which often centers around small and nimble yet lightly-armed vessels.

Regional Security Ripple Effects: Threats to South Korea, Japan, and U.S. Interests

The emergence of a blue‑water capable DPRK navy reshapes the maritime security calculus in the region. South Korea, Japan and the United States have long relied on the predictability of a North Korean force confined to coastal waters. The introduction of destroyers capable of operating far from the Korean Peninsula and submarines that can remain submerged for extended periods “covers vast distances,” undermines existing early‑warning architectures and forces allied navies to contend with a mobile, sea‑based nuclear threat. A destroyer equipped with vertical launch systems can “launch missiles from this retrofitted naval force—an absolute game changer in case of sustained conflict.” This capability threatens commercial shipping lanes that traverse the Yellow Sea and East China Sea, potentially creating “a logistical nightmare” for regional economies. Moreover, the survivable second‑strike capability of nuclear‑powered submarines means that even a successful pre‑emptive strike on North Korean land‑based missile sites would not eliminate the DPRK’s ability to retaliate. The source emphasizes that such a scenario would render the North “almost untouchable,” as any action against it would “be almost guaranteed to provoke a massive response." In sum, the upgraded navy forces regional actors to reassess force postures, expand maritime surveillance, and consider new deterrence measures to counter a North Korean fleet that can now threaten both military targets and critical commercial routes across the western Pacific. (TITLE): North Korea's Navy is Getting Dangerous When the DPRK has previously been in the headlines for military aggression, it has almost always been regarding their missile programs—whether that’s a new test they’ve conducted, a flyover of Japanese airspace, or belligerent threats made against their neighbor to the South. As outlined by US Commander Timothy Boyle, writing for Just Security Journal (quote:) “Such a strategy should involve building a maritime security coalition, closing gaps in international law, leveraging information transparency, applying targeted diplomatic pressure, strengthening Taiwan’s maritime defences, and using legal tools as instruments of deterrence”. Interestingly, just one month earlier, on the morning of January 3rd 2025, the Trans-Pacific Express (TPE) cable, which connects Taiwan to the US, Japan, South Korea, and China, was also damaged.

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FAQ

What is the central development in North Korea’s Navy Shifts From Coastal Guard to Open‑Sea Threat?

What remains uncertain right now?

The most visible symbols of the navy’s modernization are the Choe Hyon‑class destroyers. However, the success of these strategies and how quickly they can be implemented remains uncertain.

Why does this matter strategically?

The shift in naval capability aligns with several strategic imperatives articulated in the source material. You see, his sentence - while decried by many as a travesty of justice - had been no trifling matter.

What indicators should observers monitor next?

The emergence of a blue‑water capable DPRK navy reshapes the maritime security calculus in the region. The construction of such a vessel in and of itself should raise concerns that Pyongyang has begun to move away from its historic naval strategy of focusing on coastal defense in case of a land-based invasion, which often centers around small and nimble yet lightly-armed vessels.

Sources

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Jackson Reed

Jackson Reed creates and presents analysis focused on military doctrine, strategic competition, and conflict dynamics.

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