The Navy Faces an Unprecedented Threat as China, Russia, and North Korea Ramp Up Their Submarine Warfare Game

The past two years have placed the Navy in a challenging position. The U.S. faces a significant strategic threat from the development of new unmanned underwater vehicles (UUVs) by Russia and North Korea. These countries are part of the growing “Joint Sword” military coalition, which also includes China and Iran. The alliance has recently intensified its joint naval exercises, all while developing devices with unprecedented nuclear capabilities.

The “new” submarine warfare. In March, China, Iran, and Russia conducted a joint naval exercise in the Gulf of Oman, a vital waterway near the mouth of the Persian Gulf. A similar staging occurred months later when Russia deployed its fleet alongside China during the Okean-2024 navy exercises.

From a geopolitical perspective, the Joint Sword coalition raises concerns for global military strategists, particularly regarding the U.S. Navy and its allies. The UUVs being developed are theoretically capable of carrying nuclear payloads and could generate what experts have termed “radioactive tsunamis.” This could eventually transform modern maritime conflict dynamics into something entirely unprecedented.

North Korea’s Haeil system. Earlier this year, the BBC reported that North Korea claimed to have conducted the first test of its “Haeil-5-23” system in response to joint military exercises involving the U.S., South Korea, and Japan. The system is an underwater drone capable of carrying nuclear weaponry and was reportedly tested off the country’s east coast.

The underwater drone measures 52 feet in length and has an estimated range of 620 miles. It’s designed to carry either nuclear or conventional warheads, targeting locations in South Korea and Japan. Currently powered by a diesel-electric propulsion system, the Haeil must be launched from land or modified platforms. This is because North Korea doesn’t possess submarines large enough to deploy it.

While there was no independent confirmation of the test, the North Korean claims followed existing suspicions. Since 2023, the Asian country has claimed advancements in its Haeil system, suggesting it can infiltrate enemy waters and cause significant underwater explosions. Although the nation has portrayed these weapons as innovative, analysts argue that their threat may be minor compared to nuclear ballistic missiles. According to Ahn Chan-il, a researcher at the World Institute for North Korea Studies, the Haeil system is still in the testing phase.

Russia’s Poseidon. In 2023, Russia made further developments in Poseidon, a nuclear-powered underwater torpedo capable of devastating coastal cities through radioactive tsunamis. The weapon was first revealed in 2015 and reportedly tested in 2016. It combines extreme autonomy with a nuclear design that challenges current defense capabilities. Some reports suggest Russia plans to produce at least 30 of these torpedoes and will deploy them on modified submarines to accommodate their size and weight.

Poseidon features a compact nuclear reactor and can travel at speeds of 115 mph, covering distances of up to 6,200 miles while operating at depths of 620 miles. Designed to evade detection through advanced acoustic tracking technologies, its destructive capability includes a nuclear payload with an estimated yield of several megatons. In fact, it could potentially reach up to 100 megatons and significantly exceed the yield of Russia’s Tsar Bomba, the most powerful nuclear bomb ever tested.

The impact of Poseidon on strategic stability. The development of Poseidon reflects Russia’s response to the U.S. withdrawal from the 1972 Anti-Ballistic Missile Treaty, which President Vladimir Putin described as “the cornerstone of strategic stability.” The Poseidon torpedo aims to overcome U.S. missile defense systems, allowing for attacks on aircraft carrier groups and coastal targets. This would also reinforce Russia’s nuclear doctrine of “escalate to de-escalate,” which involves using nuclear threats to achieve strategic objectives.

Moreover, Poseidon highlights the risks associated with autonomous systems in the nuclear domain, where reduced human control can increase the likelihood of mistakes and misunderstandings during crises. This raises critical questions about the ethics and safety of these kinds of technologies.

Radioactive tsunamis. The operational concept of Poseidon and Haeil may violate principles of international law regarding weapon usage. Nuclear detonations intended to generate radioactive tsunamis could be classified as prohibited environmental modification techniques under the ENMOD Convention. Additionally, the catastrophic and long-term effects on the environment and human populations could contravene the provisions of Additional Protocol I to the 1949 Geneva Conventions.