In late 2025, Asia’s strategic balance began quietly but decisively shifting. Japan, Vietnam, and the Philippines, which once operated on parallel tracks, are increasingly converging in response to China’s assertiveness and uncertainties in U.S. policy. This emerging alignment signals a new power geometry shaping security, diplomacy, and economic strategy across the Indo-Pacific.
AMBASSADOR ANIL WADHWA, IFS (R) | FOR NEWS ANALYTICS
5 mins read.
In the waning weeks of 2025, a subtle but unmistakable shift in Asia’s strategic architecture had crystallised. Across the vast expanse of the Western Pacific—from the calm waters off Tokyo Bay to the contested reefs of the South China Sea—three capitals once seen as disparate actors are finding a shared geopolitical rhythm. Japan, Vietnam, and the Philippines—countries with very different histories and domestic pressures— are increasingly synchronised in their responses to China’s growing assertiveness and the broader U.S.–China rivalry. This convergence, marked by new defence ties, diplomatic outreach, and shared economic interests, signals a new power geometry in Asia that could redefine regional dynamics well into the next decade.
STRATEGIC CONVERGENCE
For years, the security landscape of East and Southeast Asia was anchored on the formidable U.S.–Japan alliance and the U.S.–Philippines Mutual Defence Treaty. But recent events have accelerated a more layered network of relationships that blends bilateral pacts with pragmatic cooperation. Tokyo and Manila, once linked largely by economic ties and post-war reconciliation, have now woven defence into the core of their partnership. In 2025, Japan and the Philippines concluded a historic military pact, the Reciprocal Access Agreement (RAA), which entered into force on 11 September 2025. This pact allows forces from both countries to operate on each other’s territory—a profound departure from their traditionally restrained defence postures. The RAA reflects how dwindling faith in the United States and deepening trust amongst Asian countries have translated into operational cooperation in the face of common strategic concerns over China’s rise and its growing and demonstrated maritime dominance.
The Japan–Philippines Reciprocal Access Agreement marks a decisive break from restraint, signalling that middle powers are translating shared anxieties into operational military cooperation.
ALLIANCE REWIRING
Beyond treaties, the three nations have engaged in tangible military cooperation. Through a series of Multilateral Maritime Cooperative Activities (MMCAs) in 2025, the Philippines, http://www.newsanalytics.in sweeping assertion of maritime rights that overlaps with the Japan, and the United States conducted joint exercises within the Philippines’ Exclusive Economic Zone. Anti-submarine exercises, maritime domain awareness, and interoperability appear to be directed at countering the threat perceived from China’s expanding naval and military capabilities. Japan has also been exporting critical military technology to the Philippines. In late 2025, Japan agreed to provide the Philippines with a Japanese-made command and control system designed to improve radar integration and situational awareness. This transfer reflects a shift from Japan’s traditional emphasis on capacity-building to more assertive moves towards strengthening regional networks.
Unlike Japan and the Philippines, Vietnam has long pursued a careful balancing act with China. Vietnam shares a long land border with Beijing and has historically prioritised peaceful coexistence even as it contests overlapping maritime claims in the South China Sea. But Vietnam’s strategy is evolving. While not an American treaty ally, Vietnam has steadily expanded pragmatic security ties with both the United States and Japan, strengthening its capabilities while ensuring that such actions do not provoke a Chinese reaction. The United States, recognising Vietnam’s geopolitical importance, elevated ties by designating Vietnam as a “comprehensive strategic partner” in 2023. Defence cooperation has been discussed, but arms sales have remained constrained and limited. Although Vietnam and the Philippines have historically navigated overlapping claims in the South China Sea, they have nonetheless sought practical cooperation on maritime security and incident prevention, in which China is also a participant.
CHINA FACTOR
China’s posture in the South China Sea remains the central pivot around which this new alignment rotates. From orchestrated naval drills to enhanced coast guard operations, China has intensified its presence in contested waters. China’s recent live-fire exercises and night manoeuvres in the South China Sea are part of a strategic policy decision to strengthen its maritime claims while demonstrating its capabilities. These actions occur against the backdrop of China’s expansive claims through the “nine-dash line”, a sweeping assertion of maritime rights that overlaps with the exclusive economic zones of several ASEAN claimants. In 2016, an arbitral tribunal rejected these Chinese claims, but China continues to assert rights over the waters encompassed by the nine-dash line on the basis of historical claims that have no place in modern international law. In 2025, a collision between a PLA Navy warship and a Philippine vessel occurred near Scarborough Shoal, raising tensions. The incident underscored the risks inherent in a crowded security environment where routine patrols can turn volatile. China has criticised Japan’s expanding role in Southeast Asian security, framing it as meddling in waters where Japan has no territorial claims.
China’s actions in the South China Sea are no longer isolated provocations but catalysts accelerating regional alignment against unilateral dominance.
No discussion of Asia’s shifting power geometry is complete without accounting for the broader U.S.–China rivalry. In 2025, Washington actively reassured partners in the region of its commitment to a “free and open Indo-Pacific”, even as policy nuances were discernible under the Trump administration. The most glaring change has been the calibrated U.S. approach to South China Sea incidents. U.S. initiatives, such as the new joint task force with the Philippines to deter coercion in disputed waters, strengthen deterrence and reassure smaller states of continued U.S. engagement. However, much of the U.S. approach is shaped by domestic political dynamics and a broader strategic calculus that weighs the risk of direct confrontation with China. Consequently, Japan and the Philippines have leveraged U.S. security guarantees while also hedging. The Philippines, for instance, has acknowledged that it might need to defend itself unilaterally in the initial stages of a crisis. This reflects concerns about the speed and reliability of allied reinforcements from partners like the United States in a high-intensity, fast-moving conflict.
ASEAN DILEMMA
Meanwhile, Japan’s own security identity has undergone a profound transformation. In late December 2025, Tokyo approved a record-high defence budget exceeding ¥9 trillion (approximately $58 billion). It has spoken of accelerating modernisation and expanding strike and coastal defence capabilities. This reflects growing concern vis-à-vis China’s aggressive actions in the region. ASEAN finds itself at a crossroads in this new geometry. On paper, ASEAN champions neutrality and dialogue. Yet the bloc’s inability to agree on a firm stance towards China’s maritime claims highlights its internal divisions.
The Philippines assumes the ASEAN chairmanship in 2026. This could offer an incentive for the Philippines to push for a legally binding Code of Conduct with China that would stabilise the region, but ASEAN’s capacity to harness this moment effectively and in its favour remains doubtful. Strategic convergence is not limited to security. Japan and the Philippines have advanced economic cooperation through initiatives such as the Luzon Economic Corridor, aimed at boosting connectivity and resilience. These projects signal that the emerging power geometry blends military readiness with concerted economic planning. Hanoi, too, is anchoring part of its strategy in economic diversification and defence modernisation.
FLEXIBLE ALIGNMENTS
Vietnam’s comprehensive strategic partnerships span not only Western capitals but also regional neighbours. Vietnam appears to have mastered the art of nuanced balancing, ensuring it is not overly reliant on any single country. Indeed, as power competition intensifies, countries such as Japan, Vietnam, and the Philippines are carving out strategic space that emphasises flexible alignment and practical cooperation over rigid blocs.
This convergence is not a formal alliance but a flexible strategic mosaic, redefining Asian security beyond rigid blocs and singular power centres.
In the near term, further deepening of cooperation among Tokyo, Hanoi, and Manila is likely. This may occur through defence dialogues, interoperability exercises, and joint maritime surveillance efforts. Japan is expected to continue enhancing its strategic footprint in Southeast Asia. It will neither provoke China nor challenge China’s core interests, but it has already emerged as a hedge against unilateral dominance. For Vietnam, the balance will remain delicate. It will continue to expand external partnerships to mitigate risk while avoiding overt alignment that China could construe as containment. This calibrated approach reflects Vietnam’s longstanding emphasis on strategic autonomy, or bamboo diplomacy, while safeguarding its sovereign interests. The Philippines, driven by growing public and political sensitivity to Chinese incursions, is likely to sustain its defence partnerships and press ASEAN for concrete mechanisms to regulate conduct in disputed waters. Philippine naval capabilities and defence doctrine will evolve alongside these relationships.
For India, the convergence of Tokyo, Hanoi, and Manila reinforces the strategic logic of the Indo-Pacific as a connected maritime theatre. It complements India’s partnerships with Japan, Vietnam, and ASEAN, strengthens norms against coercion in the South China Sea, and supports India’s pursuit of strategic autonomy and regional stability. Finally, the U.S.–China rivalry will shape, but not wholly define, this convergence. The U.S. presence provides reassurance, but in light of recent U.S. actions, regional states are crafting their own agency, forming overlapping networks that seek not merely to balance China but to uphold a rules-based order in Asia. In this new power geometry, Tokyo, Hanoi, and Manila are not formal allies in the traditional sense. Rather, they represent a mosaic of strategic, diplomatic, and economic convergences that together signal a rebalancing of influence in Asia. As China watches closely, and as countries in Southeast Asia chart their own trajectories, the contours of the 21st-century regional order are being drawn—not by a single power, but by a constellation responding to changing tides.
(Ambassador Anil Wadhwa, IFS (R) is a former Secretary (East) in the Indian Ministry of External Affairs and has served as Ambassador to Italy, Thailand, Oman and Poland. The views expressed are of the author and do not necessarily reflect the views of The News Analytics Herald.)
QUICK INSIGHTS
- Japan, Vietnam, and the Philippines are aligning in response to China’s growing maritime assertiveness.
- Defence cooperation is deepening through new treaties, joint exercises, and technology transfers.
- China’s South China Sea actions are accelerating regional strategic convergence.
- ASEAN’s internal divisions limit its ability to shape collective regional security responses.
- The Indo-Pacific balance is shifting towards flexible alignments rather than formal alliances.
