Multiple Lines of Pressure: In-Depth Analysis of Three Major Trends in PLA South China Sea Exercises, Japan's Rare Passage Through Shipping Lanes, and the Militarization of Artificial Intelligence

In late April 2026, the People's Liberation Army of China showcased three sets of military actions and policy signals with far-reaching strategic significance within less than a week, covering maritime power projection, the expansion of oceanic operational channels, and the accelerated application of artificial intelligence in the military field. These three seemingly independent clues are, in fact, resonating under the same strategic logic, reflecting the systematic advancement of the Chinese military in three dimensions: regional denial, realistic training, and intelligent transformation.

On April 24, a naval formation belonging to the Southern Theater Command completed a live-fire exercise in the waters east of Luzon Island in the Philippines, with the Type 055 destroyer "Zunyi" (hull number 107) as the flagship. This exercise was publicly announced by the Southern Theater Command and was officially described as a "necessary action to respond to the current regional situation." Notably, the timing of the exercise coincided with the start of the U.S.-Philippines "Balikatan 2026" joint military exercise on April 21—this is a large-scale annual bilateral exercise lasting 19 days. From the video footage released by the South China Sea Network, the "Zunyi" led a formation of at least four vessels, conducting multi-subject training. The Type 055 destroyer is currently the most advanced surface combat platform in the Chinese Navy, with a full-load displacement of about 12,000 tons, equipped with a 112-cell vertical launch system capable of carrying YJ-21 hypersonic anti-ship ballistic missiles. The choice to lead with this type of ship in the waters east of the Luzon Strait serves, on one hand, to geographically position itself close to the key area of the U.S.-Philippines joint exercise in northern Luzon, and on the other hand, demonstrates the Chinese Navy's willingness and capability to maintain a continuous presence outside the first island chain.

Almost simultaneously, actions from the Eastern Theater Command were also noteworthy. On April 19 and 23, two formations from the PLA's 133rd Fleet successively traversed two international waterways in the southwestern waters of Japan—on April 19, they entered the western Pacific via the Yokoate Channel for training exercises, and on April 23, they returned through the Yonaguni-Iriomote Waterway. The Eastern Theater Command explicitly stated in its announcement that this action "effectively tested the troops' capabilities for distant sea operations." The Yonaguni-Iriomote Waterway is located between Yonaguni Island and Iriomote Island at the westernmost end of Japan, with Yonaguni Island being only about 110 kilometers from Taiwan. This marks the first known record of a PLA naval vessel publicly traversing this waterway. Former PLA instructor Song Zhongping candidly stated that this move serves as a "clear warning" to Japan and can also be seen as an indirect signal regarding the Taiwan issue. From a military geography perspective, the opening of this waterway means that the PLA Navy has added another route for entering and exiting the western Pacific beyond the Miyako Strait, which helps to alleviate the monitoring pressure on the southwestern islands from the Japan Self-Defense Forces.

While maritime power continues to expand, the PLA has also made significant strides in the theoretical construction of intelligent warfare. On April 24, the PLA Daily published a commentary article using the Iran War as a case study, systematically discussing the "strategic value" of artificial intelligence in modern warfare. The article pointed out that the Iran War was the first real-world case where artificial intelligence was integrated throughout the entire combat cycle—from intelligence analysis, target identification, operational planning to damage assessment—"empirically validating the broad application prospects and significant strategic implications of artificial intelligence in the military field." The article positions artificial intelligence as the "core engine" for reshaping the forms of warfare, military organizational structures, and global strategic patterns, emphasizing the "inevitability" and "urgency" of the PLA accelerating the transformation of AI technology into combat effectiveness. Specifically, the article highlights the "proactive warning" intelligent situational awareness system—which can provide threat warnings and predict enemy intentions while real-time identifying targets and tracking enemy movements. This description aligns closely with the PLA's recent promotion of the "intelligent joint operations" concept and resonates with the AI-assisted command decision-making systems showcased by several military-industrial enterprises since 2024.

When examining these three clues together, a clear picture emerges. In the South China Sea direction, the surface formation centered around the Type 055 destroyer is extending the conventional training area from within the South China Sea to the east of the Philippine archipelago, indicating that the Chinese Navy's control capabilities over the critical passages of the Bashi Channel and the Luzon Strait are being tested in real combat scenarios. In the direction from the East China Sea to the western Pacific, the activation of new waterways indicates that the PLA Navy is systematically expanding its oceanic entry and exit routes, reducing reliance on existing international waterways. On a technical level, the official discourse from the PLA Daily releases a clear policy signal: artificial intelligence is not just an auxiliary tool but the core driving force of future warfare. The intersection of these three lines represents the strategic goal of the Chinese military's comprehensive transformation from "mechanized and informational composite development" to "intelligentization."

It is worth continuing to monitor whether the U.S.-Philippines "Balikatan 2026" exercise will continue until early May, and whether the PLA Southern Theater Command will conduct more targeted training exercises during this period remains to be seen. Additionally, the Japanese Ministry of Defense's subsequent response to the Yonaguni-Iriomote Waterway crossing incident, as well as any adjustments to the defense deployments of the southwestern islands, will also be important follow-up directions.