Naval Diplomacy and Strategic Signaling in a Multiplex Rules‐Based Order: Australia, Japan, and India's Engagements With the Philippines

ABSTRACT Why do states conduct naval diplomacy? While existing literature highlights its diplomatic utility, it often drowns in tautology. To escape the pit, the article asks: why do states conduct naval diplomacy in the 21st‐century Indo‐Pacific? It argues that naval diplomacy is a signaling act to communicate contributive status in a multiplex maritime order. Using Liberal Realism and Smart Power logic, the article compares Australia, Japan, and India's engagements with the Philippines. It finds that naval diplomacy signals legitimacy and adaptation—not just diplomatic functions. Order Contributors (Australia, Japan, and India) shape the rules‐based order on their terms, while Order Stakeholders (Philippines) assert agency to sustain regional public goods. The article challenges binaries like the China–United States Thucydides Trap that beset the Indo‐Pacific and reframes the strategic logic of contemporary naval diplomacy.