Building Undersea Power: How China Aligns Strategy, Platform Development, and Operational Practice

Building Undersea Power: How China Aligns Strategy, Platform Development, and Operational Practice

Undersea warfare is often regarded as one of the most complicated areas of modern military operations. Imagine that you are an anti-submarine operator; how do you distinguish submarines from background ocean noises like marine wildlife? Detection is constrained by the physics of sound propagation and platforms operate with limited situational awareness. Most scholars assess that the People’s Liberation Army Navy’s (PLAN) undersea warfare capacity is far behind that of Western navies. However, the PLAN has started to address its shortcomings, spanning operational and system-management flaws, as well as gaps in training and doctrine. This process is advancing on three parallel tracks: strategic planning, platform development, and operational practice.

Strategic Planning

According to the Science of Military Strategy 2020, China views the deep-sea domain as a new arena for military conflict and is expanding its national interests into this environment. In the PLAN’s analysis, the deep-sea domain has become a strategic area where major countries seek to seize an advantage. First, the battlefield environment is highly challenging, easy to attack but difficult to defend due to poor visibility, complex hydrological conditions, and acoustic variability. Second, the operational space is vast, encompassing both vertical domains (shallow to deep water, seabed, and associated air, space, cyber, and electromagnetic spaces) and horizontal domains (near-shore, offshore, and the open ocean). Third, deep-sea operations involve systematic, multi-domain confrontation, supported by networked information systems and engagement across multiple services and maritime forces. In this context, China is developing advanced technologies to exploit the undersea environment, achieving strategic deterrence and sustaining operational advantage.

Platform Development

The PLAN is modernizing its underwater forces by integrating both submarines and uncrewed underwater vehicles (UUVs). According to the U.S. Department of Defense’s 2024 report on Military and Security Developments Involving the People’s Republic of China, the PLAN possesses six nuclear-powered ballistic missile submarines and six nuclear-powered attack submarines. These platforms reflect China’s technological advancements, such as the Type 093 mounting vertical launch systems for multiple types of cruise missiles, as well as serving strategic purposes. In the near seas, these submarines obstruct potential adversary operations, enhancing China’s anti-access/area-denial posture. Nuclear-powered platforms also extend China’s operational reach into the far seas, potentially enabling sustained presence and deterrence beyond the First Island Chain. This signals a transition toward integrated near- and far-seas capabilities. 

In addition, uncrewed vehicles are gradually playing a vital role in how submarine and anti-submarine warfare is conducted. At the 2025 Dubai Airshow, China unveiled its first hunter-killer submarine drone, called the Wing Loong X, designed for anti-submarine warfare. In September, Naval News revealed that the PLAN was testing two uncrewed submarines off Hainan in the South China Sea.  Also, the Philippine Coast Guard recently discovered a Chinese-made UUV in the South China Sea. Taken together, these developments indicate that China is betting on new undersea technologies to gather intelligence, bolster surveillance, enhance reconnaissance, and maintain adaptability in complex underwater environments.

Operational Practice

Strategy can only be validated through extensive practice. China’s training on undersea warfare has focused on two distinct dimensions: internal training from tactical to operational levels, and real-world deployment from near-seas to far-seas operations. 

Two recent articles by the PLA Daily provide evidence of these efforts. PLAN submarine crews have integrated simulated operational environments and data-driven analysis to refine tactics and improve real-world performance. Also, the PLAN has employed self-developed anti-submarine wargames, combining adversarial simulations with realistic environmental modeling. These practices allow crews and commanders to build their capacity at both the tactical and operational levels. By evaluating operational concepts and refining decision-making, the PLAN can translate lessons learned from simulations into real-world scenarios.

Concerning real-world readiness, the PLAN and its anti-submarine helicopter units conducted intensified patrols and training exercises in the southwestern and eastern waters off Taiwan in 2024. These activities suggest that the PLAN is likely to practice anti-submarine warfare and boost its underwater capabilities in its near-seas region. Furthermore, China conducted the second iteration of exercise NORTHERN COOPERATION with Russia in September 2024, which was reportedly followed by a combined naval patrol in the Sea of Japan, including anti-submarine warfare and sea rescue training. In August 2025, a Chinese submarine visited Russia for the first time for joint drills called Maritime Interaction 2025, demonstrating the PLAN’s growing capability to operate in distant waters and participate in multinational exercises. These activities show that China’s underwater ambition appears to extend from the near-seas to the far-seas areas.

With these across-the-board approaches, China is bridging the gap between theory and practice and strengthening both near-seas denial and far-seas operational capabilities. As China’s capabilities continue to mature following this pattern, regional maritime security dynamics are likely to become increasingly complex, raising the stakes for any potential contingency in the Western Pacific and beyond.