Behind Kim’s nuclear navy and AI lies Beijing

North Korea’s pursuit of nuclear weapons and an expanding missile arsenal reflects a rational calculation common to states that perceive an existential security threat: nuclear capability functions as the ultimate guarantor of regime survival and as a deterrent against a far stronger adversary.

This is not the puzzle this analysis sets out to examine. The puzzle is how Pyongyang has sustained and accelerated this pursuit while subject to one of the most extensive multilateral sanctions regimes in modern history, with its official trade totalling a mere US$2.7 billion in 2024. The answer lies substantially in a longstanding defence relationship with China, and in the economic leverage Beijing extends to Pyongyang almost without limit.

The result is not asymmetric dependency alone but a structure of mutual strategic convenience: an arrangement that suits both capitals, and that has been reaffirmed most recently by Chinese President Xi Jinping’s state visit to Pyongyang on 8 and 9 June 2026.

A longstanding defence relationship

China and North Korea’s defence cooperation rests on a formal foundation unmatched anywhere else in Beijing’s diplomacy. The 1961 Treaty on Friendship, Cooperation and Mutual Assistance — signed by Zhou Enlai and Kim Il Sung in the aftermath of China’s direct military intervention in the Korean War — remains the only mutual defence pact China holds with any state. Article II commits both sides to immediate assistance should either face external attack, and the treaty has been renewed every 20 years since, most recently in 2021 — surviving the end of the Cold War, the collapse of Soviet patronage and repeated North Korean nuclear and missile tests that have periodically embarrassed Beijing internationally.

The treaty’s origins help explain its remarkable longevity. China entered the Korean War in October 1950 at enormous human cost to prevent a unified, US-aligned Korea from emerging on its border. A decade later, the 1961 pact formalised that strategic commitment. It also served two immediate purposes: countering Soviet influence as the Sino-Soviet split deepened and providing Pyongyang with a firm security guarantee after South Korea’s 1961 military coup.

That the treaty has survived long after the ideological circumstances that gave rise to it is striking. Unlike North Korea’s 2000 Treaty of Friendship, Good Neighbourliness, and Cooperation with Moscow, which replaced its automatic military assistance clause with looser consultation language, the China-North Korea defence treaty remains the more structurally binding of Pyongyang’s two great-power alliances — at least on paper.

This durability reflects continuity of interest rather than sentiment alone. China has consistently valued North Korea as a buffer state separating its northeastern industrial heartland from American forces stationed in South Korea, a strategic calculation unchanged since 1950. The relationship’s military dimension was visibly reinstitutionalised at the June 2026 summit, where Chinese Defence Minister Dong Jun met his North Korean counterpart No Kwang-chol alongside Xi and Kim, and where both sides pledged to enhance exchanges in diplomacy, law enforcement and military affairs, marking a more overt ministerial-level defence channel than was visible in recent years.

China’s leverage over North Korea is grounded in economic indispensability. Beijing accounts for 98% of North Korea’s official trade, supplies crude oil through the Dandong-Sinuiju pipeline operated by the state-owned China National Petroleum Corporation and has expanded bilateral trade significantly even within the sanctions period. Trade data for February 2026 showed Chinese exports to North Korea rising 58.3% year on year, extending a recovery driven by the resumption of cross-border rail and air links, including the restoration of Air China flights to Pyongyang in March 2026.

This economic relationship gives Beijing a lever it can tighten or loosen according to its own diplomatic priorities with Washington, while giving Pyongyang the material base, fuel, hard currency and industrial inputs — without which neither its economy nor its weapons programmes could function. China’s diplomatic protection compounds this leverage: Beijing and Moscow have blocked further UN Security Council sanctions since 2017 and, in 2024, acquiesced in dissolving the UN Panel of Experts that had monitored sanctions enforcement since 2009. The result is an economic and institutional architecture that insulates North Korea from the full weight of the sanctions regime while preserving China’s capacity to influence Pyongyang’s behaviour at will.

From warheads and warships to battlefield AI

North Korea’s nuclear weapons programme has continued to expand under this protective architecture. The US Defense Intelligence Agency assessed in 2025 that North Korea has restored its nuclear test site and is postured to conduct a seventh nuclear test at a time of its choosing, while the International Atomic Energy Agency reported in March 2026 the ongoing operation of uranium enrichment facilities at Kangson and Yongbyon, alongside a new building at Yongbyon resembling the Kangson facility. Independent experts estimate North Korea has produced sufficient fissile material for up to 90 warheads and may have assembled approximately 50. Following the February 2026 Ninth Party Congress, North Korea formally declared its position as a nuclear weapons state to be irreversible and permanent.

North Korea’s most recent advances extend beyond traditional missile and nuclear development into artificial intelligence and autonomous systems. In September 2025, Kim declared artificial intelligence development a top priority during a visit to Pyongyang’s Unmanned Aeronautical Technology Complex, overseeing tests of multipurpose drones and unmanned surveillance aircraft. By mid-2026, North Korea claimed to have successfully tested AI-guided missiles capable of striking targets up to 100 kilometres away, employing computer vision systems designed to track targets even in GPS-jammed environments, a capability consistent with battlefield innovations observed elsewhere, including drone warfare in Ukraine.

This pivot toward AI-enabled and unmanned systems reflects North Korea’s recognition that it cannot match its adversaries in conventional military mass, but may be able to offset this disadvantage through asymmetric, technologically enabled capabilities. The extent to which Chinese commercial and dual-use technology transfers, components, processors and sensor technology routed through Chinese intermediaries underpin this AI and drone development remains difficult to verify precisely. However, it is consistent with the broader, well-documented pattern of Chinese-origin dual-use goods reaching North Korea’s defence-industrial base through shell companies and transshipment networks, as repeatedly identified in US Treasury sanctions designations of PRC-based procurement networks.

North Korea’s naval transformation

North Korea’s maritime dimension has undergone the most dramatic transformation in decades. After commissioning the Choe Hyon, its first 5,000-tonne guided-missile destroyer, at the Nampho Shipyard in late June 2026, Kim declared that the vessel ends over 70 years of naval stagnation and that the nuclear armament of his navy is proceeding as planned. On 3 July 2026, Kim personally supervised weapons trials aboard the Kang Kon, the second destroyer of the same class, which had been repaired following a widely publicised capsizing during its launch ceremony in May 2025.

The Kang Kon’s trials included the test-firing of a nuclear-capable strategic cruise missile, naval artillery, automatic cannons as well as an integrated electronic warfare and target-detection suite, with Kim subsequently ordering the vessel into active service within two months. These two destroyers are the vanguard of a stated ambition to commission at least two 5,000-tonne surface combatants annually for five years, alongside a planned 10,000-tonne strategic warship. South Korean officials and analysts assessed that the Choe Hyon was likely built with Russian technical assistance, a judgement consistent with the deepening Russia-DPRK military cooperation that has accelerated since 2022.

Taken together, the Choe Hyon and Kang Kon programmes represent a strategic shift from the land-centric deterrence posture Pyongyang has maintained for decades toward a nascent sea-based nuclear strike architecture, one that seeks to diversify the launch vectors available to Pyongyang, complicate allied pre-emptive strike planning and reduce the vulnerability inherent in fixed, land-based missile sites.

China’s economic and technological patronage, sustaining the shipbuilding capacity and industrial inputs required for this naval expansion, forms the material foundation beneath what is, in strategic terms, an attempt by Pyongyang to leverage its great-power relationships to shift the correlation of forces on the Korean Peninsula in its favour.

North Korea has paired this broader technological diversification with parallel investment in long-range conventional strike capabilities, including strategic cruise missile and anti-air missile tests in late 2025. Taken together, the nuclear, missile, naval and emerging-technology programmes form an integrated modernisation effort rather than isolated initiatives, one that draws on decades of Chinese-origin industrial capacity even as Pyongyang increasingly emphasises domestic production to reduce traceable dependency on any single supply chain.

A 65-year shield

China’s defence cooperation with North Korea is not a recent improvisation but rather a structural commitment 65 years in the making, and its economic leverage over Pyongyang is both total in scope and deliberate in application. Together, these two instruments have allowed North Korea to convert a rational security calculation — the pursuit of nuclear deterrence — into an operational reality.

They have an expanding nuclear arsenal, increasingly sophisticated hypersonic missile systems, a fast-developing portfolio of AI-enabled drones and precision-guided munitions, and now a nascent nuclear-capable surface fleet. None of this is paradoxical. It is the predictable outcome of an arrangement that serves both governments’ interests simultaneously. Beijing secures a buffer state, leverage over Washington and proof that sanctions cannot compel capitulation. Pyongyang secures the economic and technological lifeline without which its deterrence posture — on land, in the air, and increasingly at sea — would be unsustainable.

The June 2026 Xi-Kim summit, the most senior bilateral engagement in seven years, did not alter this calculus; it confirmed it. Neither side’s official readout mentioned denuclearisation, an omission that speaks louder than any communique language affirming friendship. For policymakers in Washington, Seoul and Tokyo, the analytical implication is unambiguous: no strategy aimed at constraining North Korea’s nuclear, missile, naval, or emerging-technology advancement can succeed without directly addressing the Chinese defence and economic architecture that makes this advancement possible. Sanctions targeted at Pyongyang alone, absent corresponding pressure on the financial and technological networks operating through China, will continue to address only the symptom of a problem whose cause lies — and will remain — in Beijing.

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