Tokyo and Canberra strengthen their military presence in the Philippines

The Philippines is experiencing an unprecedented intensification of its security partnerships. Japan and Australia are systematically expanding their defense roles in the region—a trend that is becoming increasingly clear against the backdrop of growing Chinese activities in the Western Philippine Sea and increased military presence in the Taiwan Strait.

For Japan, this year marks a quarter-century since its strategic realignment, but for now, the coming months will focus on intensified cooperation. The visit of Foreign Minister Toshimitsu Motegi at the beginning of the year resulted in two landmark defense agreements that elevate the partnership to a new level.

Japan’s Modernized Security Architecture in the Philippines

The first agreement, the Acquisition and Cross-Servicing Agreement (ACSA), establishes the legal framework for seamless logistics support. During joint operations and humanitarian missions, Japanese and Philippine forces can now mutually access resources and services—an important step forward for operational efficiency.

Additionally, Japan announced security assistance of $6 million. These funds are earmarked for building infrastructure to house rigid-hulled inflatable boats, which Japan has already transferred to the Philippine Navy. This is the first project of its kind and signals Tokyo’s long-term commitment to maritime capacity development in the Philippines.

The ACSA complements the Reciprocal Access Agreement (RAA), ratified last year, which authorizes both countries to station forces on each other’s territory for combat training and disaster response. Although Japan is legally limited to five categories—rescue, transport, warning, surveillance, and mine clearance—for arms exports, it strategically leverages this flexibility. By the end of 2025, Japan is preparing to export a command and control system designed as an air defense system. The system integrates radar and sensor data for early detection of enemy aircraft and missiles—technology that has been working alongside already transferred air surveillance radars since 2022 and significantly enhances interoperability.

Australia’s Infrastructure Offensive in the Philippines

Meanwhile, Australia is intensifying its strategic engagement. The upcoming year will see the construction of eight infrastructure projects at five military bases on Luzon—focused entirely on the Philippines—to modernize local defense capabilities. Canberra is taking the lead on construction, operation, upgrades, and maintenance.

The locations remain undisclosed for strategic reasons. Cost estimates are still pending. However, it is clear: Australia views the Philippines as a frontline in potential regional conflicts and is investing accordingly. The Australian Strategic Policy Institute has systematically analyzed this in a recent study titled “Allies Entwined,” arguing that it is in Canberra’s vital interest to support the Philippines—as a democracy under direct threat—and to preserve the rules-based regional order through international coalition efforts.

A new defense cooperation agreement between Manila and Canberra, to be signed this year, will institutionalize this collaboration. Australian Ambassador Marc Innes Brown announced that the agreement will include maritime situational awareness, joint operational planning, cybersecurity, and defense infrastructure—placing particular emphasis on the South China Sea, reflecting increased joint patrols and exercises between Manila and Canberra.

The U.S. Achilles’ Heel of Regional Stability

At the same time, the Philippines celebrates 75 years of the Mutual Defense Treaty with the United States—arguably its strongest shield. Yet, here, uncertainty is growing. The U.S. remains the most powerful ally and the only formal treaty partner—but recent political developments in Washington are causing significant concern in Manila.

The rules-based international order, upon which the post-1945 system rests, shows cracks. A comment by Canadian politician Mark Carney at the Davos Economic Forum hit the core: the strong can do whatever they want, the weak must suffer what they must. The central worry is that Trump-era transactionalism could undermine the 75-year-old American security guarantee.

That is precisely why the enhanced security partnerships with Japan and Australia in the Philippines are so significant. Both countries are deepening their engagement. The next logical step would be even closer coordination between Tokyo and Canberra themselves to collectively secure regional stability—independent of Washington’s calculated strategy. The question remains: will these middle powers seize this opportunity?