America Has a South China Sea Problem

19FortyFive  |  Andrew Latham

Chinese maritime forces recently intensified gray-zone aggressive maneuvers against Philippine vessels near Second Thomas Shoal and Scarborough Shoal, deliberate clashes engineered to exploit threshold ambiguities within the bilateral Mutual Defense Treaty. By utilizing Coast Guard units rather than PLAN warships, Beijing calibrated force levels to stay beneath the threshold of an armed attack, denying Washington a clear trigger for direct intervention.

This incremental strategy rests upon expansive Spratly Island outposts that project localized air and missile superiority over critical maritime chokepoints. Should escalatory dynamics force an allied resupply mission involving the USS George Washington strike group, the United States risks early operational disadvantages due to geographically concentrated forward facilities and constrained precision weapon inventories. The 2026 National Defense Strategy consequently emphasizes a denial defense relying on dispersed fires and submarine capabilities. To maintain credible deterrence, Washington and Manila must quietly establish private operational protocols for grey-zone thresholds before an unexpected crisis precipitates direct conflict.

Comment

The employment of maritime law enforcement hulls near Second Thomas Shoal illustrates a systematic exploitation of threshold gaps in alliance frameworks. By substituting China Coast Guard vessels for People's Liberation Army Navy combatants, Beijing creates tactical friction while staying beneath actionable triggers defined by the 1951 Mutual Defense Treaty. This grey-zone methodology transfers the burden of military escalation onto foreign commanders attempting to resupply the grounded BRP Sierra Madre. Consequently, traditional deterrence models designed around major surface combatants remain ill-suited for countering sub-lethal maritime coercion.