Journal of Indo-Pacific Affairs --
Abstract
This article examines the emergence of Japan and the Philippines as a pivotal middle-power dyad in the evolving security architecture of the Indo-Pacific. Against the backdrop of China's maritime assertiveness and growing uncertainty in US foreign policy, Tokyo and Manila have deepened bilateral cooperation across defense, economic, and strategic domains. From Japan’s unprecedented military modernization and infrastructure investments to the Philippines’ recalibrated external defense strategy, both countries are aligning to shape a more resilient and rules-based regional order. Initiatives such as the Japan–Philippines–US trilateral framework, the Luzon Economic Corridor, and Reciprocal Access Agreements demonstrate how this partnership has transcended symbolism to become a cornerstone of regional deterrence. The article assesses structural constraints, political volatility, and strategic incentives driving this cooperation while exploring its implications for broader middle-power diplomacy. Ultimately, the Japan–Philippines partnership signals a strategic shift—one where capable middle powers actively hedge against great-power uncertainty to preserve regional stability.
***
The South China Sea disputes are neither novel nor reducible to a single catalyst. China’s sweeping claims in these contested waters trace back to the chaotic aftermath of its imperial collapse in the early twentieth century, when embattled nationalist elites resorted to cartographic mythmaking and symbolic territorial assertions to reforge national identity from the ruins of dynastic decay. The so-called nine-dash line, widely associated with the People’s Republic of China, in fact mirrors earlier claims made by the Kuomintang regime—an ideological continuity that extends to Taipei’s present-day maps, if not its policy or posture.
Vietnamese and Philippine assertions over the region’s maritime features predate even this nationalist fervor, rooted instead in centuries of historical engagement—commercial, strategic, and colonial. Both states began entrenching their presence in the Spratly Islands by the mid-twentieth century, long before the term “freedom of navigation” entered the geopolitical lexicon.
Yet China’s ascension as a global power has altered the character—and the stakes—of the dispute. Over the past decade, Beijing has fused dredging with doctrine, transforming reefs into fortified forward operating bases that extend its reach and bend maritime realities to its will. In response, the United States has bolstered its presence in the theater, conducting regular freedom of navigation operations (FONOP), expanding defense cooperation with regional allies, and spearheading joint patrols with likeminded maritime democracies. The result is unmistakable: the South China Sea has become a crucible of twenty-first-century great-power rivalry.
What remains underappreciated, however, is the critical role played by middle powers—states that, while lacking the full-spectrum capabilities of superpowers, possess both the will and the weight to shape the strategic environment. Chief among them is Japan. With the world’s fourth-largest economy and one of Asia’s most capable maritime forces, Tokyo has emerged as a central architect of Indo-Pacific security. It counters China’s assertiveness, complements the United States’ regional strategy, and empowers frontline states across Southeast Asia to defend their exclusive economic zones (EEZ) and safeguard territorial integrity.
No Southeast Asian partner has proven more strategically pivotal to Tokyo than the Philippines. Over the past decade, Manila has embraced closer defense ties with Japan, particularly in response to China’s maritime coercion. Armed with Japanese-built coast guard vessels, the Philippines has taken a leading role in documenting and publicizing Beijing’s violations of international law under what has come to be known as the Transparency Initiative. The 2023 Reciprocal Access Agreement (RAA) between Tokyo and Manila institutionalized this partnership, enabling joint exercises, defense technology transfers, and operational coordination.
More consequential still is the launch of the Japan-Philippines-U.S. (JAPHUS) trilateral framework. Positioned at the nexus of the South China Sea and Taiwan Strait flashpoints, this alignment signals a maturing minilateralism aimed at deterring Chinese adventurism and reinforcing the maritime rules-based order. While the United States remains the cornerstone of regional deterrence, it is Japan—deliberate, dependable, and increasingly assertive—that is anchoring a multipolar counterweight to China’s hegemonic ambitions. In Manila, Tokyo has found both a willing partner and a strategic linchpin. Together, they represent the vanguard of middle-power diplomacy in an era defined by hardening geopolitical fault lines.
Beyond the Superpowers
The meteoric rise of China has understandably dominated strategic discourse from Washington to Canberra. In terms of velocity and scale, Beijing’s economic ascent is without precedent. In 1990, China’s nominal gross domestic product stood at a mere 6 percent of that of the United States. Less than thirty years later, it had surged to nearly two-thirds. Nowhere has this transformation been more dramatic than in East Asia, where China eclipsed Japan’s century-long economic primacy. Between 1990 and 2014, Beijing’s share of East Asia’s GDP vaulted from 8 percent to over 50 percent—an economic displacement with direct geopolitical consequences.
Over the past decade, China has entrenched itself as the world’s foremost trading nation and primary manufacturer. At the height of the COVID-19 pandemic, it stood alone among major economies in posting growth, buoyed by its monopoly over critical medical supply chains and production infrastructure. Its industrial policy—most notably the “Made in China 2025” initiative—has borne strategic fruit. China now dominates the frontier of emerging technologies, from 5G telecommunications and electric vehicle platforms to artificial intelligence and advanced materials. A comprehensive assessment by the Australian Strategic Policy Institute concluded that China leads in 37 of 44 critical technologies spanning defense, space, robotics, energy, biotechnology, quantum computing, and more.
Economic power, however, does not remain sequestered in the commercial domain; it invariably seeks strategic expression. Despite inefficiencies and debt-trap criticisms, China’s Belt and Road Initiative (BRI) has produced over 2,600 projects across 64 countries and three continents. While many of these projects remain unfinished or under scrutiny, Beijing hails the BRI as “the project of the century.” It has since launched a battery of additional initiatives—including the Global Development Initiative (GDI), the Global Civilization Initiative (GCI), and the Global Security Initiative (GSI)—designed to reframe the architecture of global governance and cast China as the new steward of international order, especially in the Global South, where it enjoys outsized political traction among local elites.
But China's ambitions extend beyond trade routes and summits. Its rise is not merely economic—it is martial. Beijing is executing a rapid and deliberate military build-up, designed not only to defend its interests but to assert them with force if necessary.
In The Rise and Fall of the Great Powers, historian Paul Kennedy noted a predictable delay between a nation’s economic ascent and its military expansion. China defies this trajectory. Rather than lag behind its economic rise, the People’s Republic has marched in lockstep, converting its newfound wealth into strategic hardware at breathtaking speed. Its modernization effort is two-pronged: enhancing asymmetric anti-access and area denial (A2/AD) systems, while simultaneously building a formidable conventional force. The results are stark. Beijing is now fielding fifth-generation aircraft carriers, advanced stealth fighters, and nuclear-powered submarines—all emblematic of its resolve to contest the regional order, if not rewrite it.
Measured in purchasing power parity, China’s defense budget ranks just behind the United States—far surpassing every other country. This is no mere vanity project. It is a calculated response to Beijing’s expanding global footprint and the vulnerabilities that come with it. In Xi Jinping’s view, economic interests must be shielded, trade routes must be defended, and access to critical maritime corridors must be secured by force, if necessary.
Yet China’s growing capabilities are not emerging in a vacuum. They coincide with rising nationalistic fervor and an assertive geopolitical agenda. Under Xi’s ideological banner of “national rejuvenation,” the Chinese Communist Party has framed its expansive maritime claims as sacred and non-negotiable. The South China Sea and East China Sea are no longer just contested waters—they are, in Beijing’s words, “blue national soil.” The phrase reveals a mind-set not of negotiation, but of entitlement.
Even more alarming is the regime’s posture toward Taiwan. A vibrant democracy and the world’s leading producer of high-grade semiconductors, the island represents not only a political defiance of Beijing’s one-party system but a strategic prize in the high-tech race that defines the twenty-first century. Beijing’s increasingly muscular rhetoric and force projection toward Taiwan signal a willingness to unify the island not through persuasion, but through coercion or conquest.
As China closes the capability gap with the United States, the Indo-Pacific slides toward a new bipolarity. Whether one calls it a New Cold War or a systemic rivalry, the underlying reality is the same: two superpowers locked in structural competition, each testing the other’s resolve, each prepared—at least rhetorically—for confrontation. In this environment, the danger is not calculated aggression but catastrophic miscalculation.
History rarely rewards complacency. And the Indo-Pacific is no place for illusions. The region is no longer a theater of balance—it is a crucible of collision.
Strategists in Washington and beyond have long wrestled with a single question: how to manage the rise of China. Nearly a decade ago, Zbigniew Brzezinski—former U.S. national security adviser and one of the last Cold War-era grand strategists—proposed a concept as audacious as it was controversial: a “Group of Two.” This G2 framework envisioned an institutionalized U.S.-China partnership, designed not merely to stabilize bilateral ties, but to co-manage the global order.
In theory, such a condominium could temper confrontation through dialogue. In practice, it risked gutting the autonomy of America’s allies and partners, especially the middle and frontline states anchoring the Indo-Pacific. The price of great-power accommodation, under this model, would be paid by those most exposed to Chinese coercion—and least able to resist it alone.
Enter the middle powers. Chief among them, Japan.
These states are neither middling in influence nor monolithic in character. They span continents, cultures, and capabilities. But they share a core distinction: the strategic autonomy to shape their environments without the full-spectrum dominance of superpowers. Middle powers act not as spectators to history, but as shapers of it.
Unlike small states, which must often hedge or bandwagon, middle powers blend material strength with diplomatic agility. What sets them apart is not size, but intent—and the means to translate intent into action. Their hallmark is multilateralism: a preference for institutions over imposition, compromise over coercion, and international norms over nationalist grievance.
As Gareth Evans—former Australian foreign minister and a leading voice on diplomatic strategy—once observed, middle powers derive their influence not merely from material capability but from the respect they command on the global stage. Their authority flows from perception as much as performance: a reputation for economic and political significance, and more normatively, for responsible international behavior. These are not states that coerce. They persuade. They do not dictate terms; they build coalitions to shape them.
Middle-power diplomacy, in its purest form, is the art of responsible influence. It is practiced by states that lack the coercive leverage to impose preferences unilaterally, yet possess the vision—and credibility—to act as stewards of international order. They engage because they must. Their security and prosperity are directly tied to the functionality of a system they cannot dominate but can help preserve.
Political scientist John Ravenhill distilled the core attributes of middle-power influence into five essential traits: capacity to defend core interests and project limited power; concentration on targeted diplomatic and normative agendas; creativity in maximizing strategic leverage; coalition-building during crises; and credibility as champions of a rules-based order. These are not the attributes of bystanders. They are the tools of states that understand both their limitations and their leverage.
Middle powers are, in essence, strategically significant democracies that have rejected the nihilism of power politics without succumbing to the naïveté of idealism. They have foresworn nuclear revisionism, but not relevance. And in an age when great powers collide and small states scramble for shelter, it is the middle powers—steady, serious, and strategically sober—that may well hold the balance.
The Japan Factor
Japan’s return to strategic relevance has been neither sudden nor accidental. It is the product of decades-long introspection, catalyzed by the collapse of its economic miracle in the waning years of the twentieth century. The so-called “Lost Decades” ended Japan’s trajectory as an ascendant global power and plunged the nation into a period of prolonged stagnation—economic, demographic, and strategic. What followed was not resignation but recalibration. A quiet strategic awakening began to stir in Tokyo.
That transformation found early expression under the reform-minded Prime Minister Junichiro Koizumi (2001–2006). Charismatic and unorthodox, Koizumi spearheaded the overhaul of Japan’s sclerotic postal system and, more consequentially, authorized the deployment of Japanese Self-Defense Forces to Iraq—a postwar first. Though these moves cost him political capital at home, they redefined the boundaries of Japanese foreign policy and inspired a generation of successors to think beyond the constraints of pacifist inertia.
Chief among them was Shinzo Abe, the most consequential Japanese statesman of the postwar era. When Abe returned to power in 2012, he did not simply govern—he set out to reforge Japan’s strategic identity. In his manifesto, Towards a Beautiful Country, Abe invoked the legacy of his grandfather, former Prime Minister Nobusuke Kishi, who sought a more reciprocal US–Japan alliance and a foreign policy befitting a sovereign nation. Abe adopted that ambition as his own, marrying it to a new geopolitical reality: the rise of China.
Beijing’s growing assertiveness, particularly in the maritime domain, presented Japan with both a threat and an opportunity. As China expanded its influence across the Indo-Pacific, Abe seized the moment to reposition Japan as a pivotal middle power—a reliable partner to the United States and a pillar of regional stability. But this assertiveness did not emerge in a vacuum. It was forged in the crucible of national trauma. Among advanced economies, no country experienced the “China shock” more viscerally than Japan, which watched its long-held industrial supremacy erode as its former wartime adversary ascended to economic dominance.
During his first, brief tenure as prime minister in the mid-2000s, Abe recognized that a stable Asia could no longer rest on US hegemony alone. America was mired in the Middle East, while China was exploiting the openness of the liberal international order to amass strategic capital. The answer, Abe believed, was coalition—an architecture of likeminded powers that could buttress regional order even in Washington’s absence.
Accordingly, he moved with conviction. He deepened strategic ties with India, identifying the world’s largest democracy as both a geopolitical counterweight to China and a natural partner. Meeting with Indian Prime Minister Manmohan Singh, Abe framed their nations as the “largest and most developed democracies of Asia,” bound by mutual prosperity and shared interests. The two leaders called for institutionalized cooperation, opening the door to a trilateral dialogue with other regional democracies.
Shortly thereafter, Abe extended the same vision to Australia’s Prime Minister John Howard, proposing a new strategic coalition—an alignment of democracies that would eventually coalesce into the Quadrilateral Security Dialogue: the Quad.
In a landmark 2007 address before India’s Parliament, Prime Minister Shinzo Abe laid bare his geopolitical vision. He spoke of a “broader Asia,” forged at the “confluence of the two seas of the Indian and Pacific Oceans,” and called upon the region’s great democracies to deepen ties across all levels of society. His message was clear: geography had gifted Asia with strategic interdependence; it was time for its democracies to turn that interdependence into alignment.
But the moment proved premature. New Delhi, wary of provoking Beijing, demurred. Australia’s Mandarin-speaking Prime Minister Kevin Rudd likewise balked, unwilling to alienate China—then Canberra’s largest trading partner. Abe’s first attempt to build a democratic coalition was shelved, an ambitious doctrine outpaced by regional caution.
He would not have to wait long for a second chance. Abe’s resounding electoral victory in 2012 returned him to power with a sweeping mandate, a repudiation of the Beijing-friendly Democratic Party of Japan and a green light to reshape the nation’s strategic posture. He vowed to “build a new country” and to “take the lead in handing over a proud and hopeful Japan to younger generations.” But his aim was larger still—a decisive break from the “postwar regime” that had constrained Japan’s foreign policy since 1945. He would bring Japan back—back into the center of Indo-Pacific geopolitics.
Armed with a parliamentary majority, Abe moved swiftly. He revised the U.S.–Japan Defense Guidelines in 2015 to bolster interoperability and strategic flexibility for the Self-Defense Forces. He consolidated national security bodies into a more coherent architecture and, most critically, reinterpreted Article 9 of Japan’s constitution, permitting collective self-defense. This was not a revolution; it was an evolution—deliberate, disciplined, and long overdue.
Abe then doubled down on his earlier strategic blueprint. He resurrected the Quad, not as a speculative forum but as a “Democratic Security Diamond”—a coalition of likeminded powers poised to counterbalance China’s hegemonic ambitions. his time, the world was ready. The Trump administration in Washington and the Modi government in New Delhi embraced the vision with vigor. Even Australia, once hesitant, now recognized the perils of strategic complacency in the face of China’s increasingly coercive posture.
The result was a revitalized and institutionalized Quadrilateral Security Dialogue under the aegis of the “Free and Open Indo-Pacific” doctrine—a blueprint aimed squarely at constraining Beijing’s revisionism, particularly in the South China Sea.
To anchor that vision in reality, Abe turned to diplomacy. Between 2013 and 2015, he visited forty-two nations, most of them in the developing world, wielding charm, capital, and credibility. Nowhere was this charm offensive more consequential than in Southeast Asia. His first foreign trip upon returning to office was to the region—not Europe, not the United States, but the Association of Southeast Asian Nations (ASEAN) capitals that would become linchpins in Japan’s strategy.
In 2013, Abe brokered a series of landmark agreements to enhance defense cooperation and economic investment with ASEAN. Gone was the reticent Japan of old. In its place stood a middle power unafraid to lead, projecting stability, prosperity, and strategic resolve across the Indo-Pacific.
The Philippines’ historic legal challenge to China’s claims in the South China Sea—filed by the Benigno Aquino administration following a tense naval standoff at Scarborough Shoal—was more than an act of defiance. It was a strategic pivot, and one that found a natural partner in Japan. With Manila seeking support for a rules-based order, Tokyo answered the call. President Aquino made repeated visits to Tokyo, where he found in Prime Minister Abe a leader ready to push beyond Japan’s traditional restraint. In an unprecedented address to the Japanese Diet, Aquino urged Japan to take on a more assertive regional role, not as a hegemon, but as a defender of international law.
Japan responded—not with fanfare, but with resolve.
Even under the controversial presidency of Rodrigo Duterte (2016–2022), whose foreign policy openly courted Beijing and whose domestic war on drugs drew international condemnation, Tokyo remained engaged. Abe was the first major foreign leader to visit Manila during Duterte’s tenure, signaling Japan’s refusal to cede regional diplomacy to China—or to moral posturing that left strategic vacuums.
Unlike many Western governments, Japan refrained from publicly castigating Duterte. Instead, Abe deployed a subtler, more strategic diplomacy—quietly encouraging Manila to adopt a public health approach to drug enforcement while maintaining a measured distance from Beijing’s economic promises, many of which remained just that: promises. In contrast, Tokyo backed its words with deeds, channeling billions into infrastructure development and capacity building across the archipelago.
Behind the scenes, Abe also played the role of mediator, helping to ease tensions between Manila and Washington at a time when bilateral relations were at their lowest point in decades. His quiet statesmanship culminated in a cordial summit between President Duterte and US President Donald Trump in Manila in 2017.
Throughout this period, Japan remained a stalwart defender of the 2016 arbitral tribunal ruling, which struck down Beijing’s sweeping nine-dash line claims under the United Nations Convention on the Law of the Sea (UNCLOS). At times, Tokyo appeared more invested in the ruling’s enforcement than Manila itself. While Duterte downplayed the ruling to preserve ties with China, Japan, alongside Australia and the United States, repeatedly emphasized its binding nature.
Within the Group of Seven (G7), Japan emerged as the principal advocate for embedding the 2016 arbitral ruling into the institutional lexicon of the world’s leading democracies. During its 2023 chairmanship, Tokyo led the drafting of a joint communiqué that left no ambiguity: “[t]here is no legal basis for China’s expansive maritime claims in the South China Sea, and we oppose China’s militarization activities in the region.” It was a diplomatic watershed—the first time the G7 spoke with collective authority on the legal dimensions of Beijing’s maritime overreach.
Undeterred by Beijing’s predictable objections, Japan doubled down the following year. Tokyo issued an unequivocal statement reaffirming that the “Tribunal’s award is final and legally binding on the parties to the dispute, the Philippines and China, under the provisions of the United Nations Convention on the Law of the Sea (UNCLOS).” It further condemned Beijing’s refusal to accept the ruling as an affront to the peaceful settlement of disputes and a violation of international legal norms. Japan’s position was not couched in the language of ambiguity. It was a call to defend order against arbitrariness—and law against lawlessness.
Japan’s motivations were not abstract. They were strategic. As a frontline state in its own maritime dispute with China over the Senkaku/Diaoyu Islands in the East China Sea, Tokyo understood that the erosion of UNCLOS in the South China Sea would reverberate across the region. The South China Sea is not just a legal battlefield or diplomatic theater; it is a commercial lifeline. Japan depends on its sea lines of communication (SLOC) for energy imports and trade. Chinese dominance in these waters would not simply challenge international law—it would place a knife to the throat of Japan’s economic security.
For Tokyo, the stakes are existential. Its repeated invocation of UNCLOS is not diplomatic theater; it is doctrine. It reflects a strategic worldview in which rules-based order is not an ideal to be admired, but a structure to be defended. In this calculus, the arbitral ruling is not just a legal precedent—it is the cornerstone of Japan’s regional security strategy and a litmus test for whether the Indo-Pacific will remain free, open, and governed by law—or succumb to the logic of might makes right.
Buoyed by the diplomatic backing of Japan and other likeminded powers, the Philippines’ national security establishment mounted a quiet but determined resistance to President Rodrigo Duterte’s most destabilizing impulses. Among these was his recurring flirtation with a Joint Development Agreement (JDA) with China—an arrangement that would have effectively legitimized Beijing’s maritime claims and violated the Philippines’ 2016 arbitral victory under UNCLOS.
Veteran diplomats and defense officials held the line. They blocked any substantive defense deals with China and successfully dissuaded Duterte from severing long-standing military ties with the United States, even as Washington’s criticism of his human rights record escalated. In the shadows of presidential bluster, institutional resilience prevailed.
Upon assuming office in 2022, President Ferdinand Marcos Jr. moved swiftly to restore strategic clarity. In one of his earliest diplomatic gestures, he met with envoys from Japan, the United States, South Korea, and India, reaffirming Manila’s commitment to the arbitral ruling and to defending the country’s sovereign rights in the South China Sea. It was an unmistakable signal: the Philippines would return to a principled foreign policy anchored in international law and democratic alignment.
Japan, in turn, continued the work Abe had begun. His successors deepened bilateral cooperation with the Philippines, visiting Manila in successive years and advancing the agenda of strategic alignment. The result was nothing short of a renaissance in Japan–Philippines relations—a new golden era of comprehensive strategic partnership.
On the economic front, Japan committed billions to high-profile infrastructure projects in the Philippines, chief among them the Manila subway system—symbolic of Tokyo’s sustained commitment to nation-building, not just diplomacy. Regionally, Japan offered a hard alternative to China’s Belt and Road Initiative. Under Abe’s leadership, Tokyo pledged USD 367 billion in infrastructure investments across Southeast Asia, a figure that eclipsed China’s USD 255 billion and redefined the balance of influence in the region.
On the global stage, Abe’s Japan did not merely react—it led. Tokyo pursued ambitious economic diplomacy, finalizing the world’s largest bilateral trade agreement with the European Union and salvaging the remains of the Trans-Pacific Partnership. Under Japanese leadership, it was reborn as the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), a testament to Tokyo’s capacity to steer multilateralism in the absence of US initiative.
Japan also joined forces with Western allies to launch a series of counter-infrastructure platforms: a USD 4.5 billion high-tech infrastructure initiative with the United States, the Blue Dot Network with the United States and Australia, and the broader Build Back Better World (B3W) initiative alongside G7 partners. Each effort underscored Japan’s strategic objective: to provide credible, transparent alternatives to China’s economic statecraft.
Crucially, Japan’s global activism was matched by a bold new defense diplomacy. It provided maritime security assistance to frontline Southeast Asian nations to help them monitor and defend their exclusive economic zones amid Chinese incursions. While Malaysia, Vietnam, and Indonesia all benefited, the Philippines stood at the center of this strategic outreach.
Manila received multirole coast guard vessels, surveillance systems, and—perhaps most significantly—Tokyo’s trust. In 2018, the Philippines hosted the first-ever postwar deployment of Japanese armored vehicles during the Balikatan exercises. Four years later, Japan dispatched fighter jets for joint drills—another historic first. These were not symbolic gestures; they were strategic milestones, marking Japan’s transition from economic donor to full-spectrum partner in regional security.
Japan has embarked on the most ambitious defense transformation in its postwar history. Under the shadow of rising threats from China and North Korea, Tokyo has not only shattered longstanding budgetary taboos but also considered acquiring its first fully operational aircraft carrier—once an unthinkable prospect in pacifist Japan. This evolution is not a rupture but the logical culmination of a trajectory set in motion by Shinzo Abe, and now carried forward with conviction by his successors.
Prime Minister Fumio Kishida, Abe’s protégé, institutionalized this legacy. Under his administration, Japan launched the Official Security Assistance (OSA) initiative—an unprecedented program aimed at funding critical infrastructure, cyber defense, and capacity building in frontline states. The Philippines quickly emerged as the primary beneficiary.
At the 2022 Shangri-La Dialogue, Kishida formally introduced a new era of “realism diplomacy.” The message was unmistakable: Japan would no longer rely on moral suasion alone. It would project power, forge partnerships, and build deterrence. He pledged to double defense spending to 2 percent of GDP, pursued the development of advanced offensive capabilities to counter evolving missile threats, and joined Britain and Italy in a trilateral effort to produce next-generation fighter aircraft.
Kishida’s commitment to the Philippines was more than rhetorical. In 2023, he delivered a historic address before a joint session of the Philippine Congress, pledging a comprehensive strategic partnership encompassing maritime security, infrastructure, and regional stability. He visited the Philippine Coast Guard and affirmed Japan’s continued support for fleet expansion—equipping the force with larger, more capable Japanese-built vessels to patrol contested waters with greater reach and resilience.
That same year, Kishida joined President Ferdinand Marcos Jr. at the White House, where they—alongside US President Joe Biden—launched the trilateral Japan–Philippines–US (JAPHUS) security framework. At its core was the Luzon Economic Corridor: a trilateral initiative aimed at securing strategic supply chains, particularly in semiconductors, energy, and critical minerals—each a linchpin of twenty-first–century deterrence.
Not long after, Tokyo and Manila formalized a Reciprocal Access Agreement (RAA), unlocking joint military drills, weapons transfers, defense technology exchanges, intelligence-sharing, and cybersecurity coordination. For two nations with military facilities situated near Taiwan, this bilateral alignment is no longer merely beneficial—it is indispensable. In any plausible scenario involving a Chinese campaign against Taiwan, Japanese–Philippine cooperation will form the southeastern flank of regional deterrence.
Given growing uncertainty over the direction of American foreign policy—particularly under a potential second Trump administration—the Japan–Philippines partnership has taken on new urgency. In early 2025, Japanese Prime Minister Shigeru Ishiba made a high-profile visit to Manila to reinforce bilateral ties in critical areas ranging from maritime security to energy and manufacturing resilience. The timing was deliberate: his visit coincided with the annual Balikatan exercises, where Japanese forces joined their US and Philippine counterparts in one of the most expansive trilateral drills to date.
The Japan–Philippines dyad has become a textbook case of twenty-first-century middle-power diplomacy—melding liberal multilateralism with hard-nosed balance-of-power realism. Yet for all its promise, the path forward remains fraught. Japan faces demographic decline and flatlining growth prospects, which may eventually constrain its ability to sustain elevated defense spending or endure extended kinetic conflict. Domestic political instability in both countries, fueled by disillusionment with establishment parties, also threatens policy continuity.
The Philippines, while enjoying robust economic growth, remains under-equipped for great-power competition. Its military modernization has been sluggish, skewed for decades toward counterinsurgency rather than external defense. Political volatility further complicates the picture, as the Marcos and Duterte factions vie for control of the nation’s strategic direction—particularly over how forcefully to confront Chinese maritime aggression.
Paradoxically, the vulnerabilities facing both Japan and the Philippines have become a catalyst for deeper bilateral cooperation—and a driving force behind broader minilateral engagement with other likeminded middle powers. Strategic necessity has created strategic opportunity.
Japan now sees the Philippines not only as a maritime partner but as a key node for expanding its manufacturing base and geopolitical footprint. With favorable demographics and macroeconomic indicators, Manila presents a long-term platform for industrial diversification and strategic investment. Tokyo, eyeing the Philippines’ rapidly growing defense budget, has also positioned itself to become a major player in the country’s arms procurement. Over the next decade, the Philippines is projected to spend approximately USD 35 billion to modernize its naval and air forces—part of a long-overdue shift from counterinsurgency to external defense. For decades, a sprawling army consumed the lion’s share of military resources, a legacy of internal conflict now being corrected as Manila recalibrates for great-power competition.
India and South Korea have emerged as early suppliers of modern weapons systems, but other middle powers—including Japan, Germany, France, Spain, and Poland—are aggressively pursuing major defense contracts. In this evolving security marketplace, Japan has more than commercial interests at stake. JAPHUS, still embryonic in function, provides a mechanism through which Tokyo—alongside Washington—can build lasting Philippine defense capacity and industrial resilience.
The Luzon Economic Corridor stands at the heart of this strategy. Under its framework, Japanese and Western firms are investing heavily in critical infrastructure, energy production, and advanced manufacturing, with a particular emphasis on semiconductors and critical minerals. The Philippines is positioning itself as a "China-free" supply-chain partner—an increasingly valuable role amid intensifying technological bifurcation and strategic decoupling.
Even a second Trump administration—skeptical of alliances and wary of free trade—would likely embrace sector-specific trade deals with Manila as part of a pragmatic effort to strengthen a frontline network of regional allies. The strategic rationale is clear: to deter any major Chinese kinetic action against Taiwan or along the contested waterways of the South and East China Seas, Washington must rely on partners with credible capabilities and shared interests.
Japan and the Philippines, for their part, have drawn the same conclusion. Both governments now acknowledge the necessity of proactive middle-power diplomacy—not merely as an adjunct to American strategy, but as a hedge against long-term uncertainties in U.S. regional posture and resolve. As Philippine Ambassador Jose Romualdez bluntly warned in the wake of what many saw as Washington’s faltering commitment to Ukraine: “t the end of the day, each country now has to be ready to be able to beef up its defense, beef up its economic security.”
Tokyo and Manila have taken that warning to heart. Their focus now is on “Trump-proofing” and “Duterte-proofing” their security relationship—insulating it from both American political volatility and Philippine populist reversals. Japan, like other Western democracies, has a vested interest in the success of the Marcos administration. Consolidating high-stakes defense and economic cooperation today offers the best chance of preserving continuity if a more China-aligned leader emerges after the 2028 elections.
The Duterte presidency demonstrated the enduring strength of institutional guardrails within the Philippine state. Despite six years of strategic ambiguity and rhetorical flirtation with Beijing and Moscow, no substantive defense or economic pacts materialized. The liberal, West-leaning establishment held firm.
Today, that same combination of strategic urgency and geopolitical unpredictability has propelled the Japan–Philippines partnership to unprecedented depth. For both nations, a rules-based regional order is not aspirational—it is imperative. It is the legal and strategic scaffolding upon which smaller and medium-sized powers depend.
Yet the Indo-Pacific remains a contested and increasingly combustible theater. Whether this emergent axis of middle powers can constrain the excesses of superpower rivalry—or prevent catastrophic escalation in the event of conflict—remains the defining question of our time.
Conclusion
The Japan–Philippines strategic partnership stands as one of the Indo-Pacific’s most consequential middle-power alignments—born not of convenience, but of necessity. As China presses forward with a revisionist agenda across the East and South China Seas, and as American regional commitments grow increasingly contingent on domestic political winds, Tokyo and Manila have assumed roles that neither sought but now must sustain: architects of regional deterrence and custodians of a fragile rules-based order.
What began as economic assistance and maritime capacity-building has matured into a multifaceted security relationship—backed by formal agreements, joint exercises, intelligence sharing, and trilateral frameworks like JAPHUS. This evolution has been driven by clear-eyed assessments in both capitals: the realization that strategic ambiguity, left unchecked, invites coercion; and that sovereignty, in this new era, must be underwritten by both resilience and relationships.
Japan’s transformation from pacifist power to proactive security actor has redefined the regional balance, not through hegemonic ambition, but through disciplined statecraft. By expanding Official Security Assistance, co-developing next-generation defense systems, and institutionalizing economic initiatives like the Luzon Economic Corridor, Japan is wielding state power with surgical precision—fortifying allies, shaping regional norms, and confronting gray-zone coercion without firing a shot. This is not rearmament for its own sake; it is geopolitical realism channeled through the logic of middle-power deterrence.
The Philippines, for its part, has shown that democratic vulnerability need not equate to strategic paralysis. The enduring influence of its liberal foreign policy establishment, despite waves of populist disruption, has ensured continuity in its alignment with democratic partners. Under President Marcos Jr., Manila has pursued long-overdue investments in external defense, while positioning itself as a “China-free” partner in semiconductor supply chains, critical minerals, and maritime domain awareness. The fact that Tokyo and Washington view the current administration as a bridgehead for long-term regional stability underscores just how central the Philippines has become to the Indo-Pacific equation.
Still, the road ahead is uncertain. Both nations face structural constraints—demographic stagnation in Japan, political volatility and under-resourced armed forces in the Philippines. And while trilateral and minilateral frameworks have multiplied, the coherence and sustainability of such efforts remain to be tested in a crisis. The looming possibility of a second Trump administration, or of a return to China-friendly leadership in Manila after 2028, only reinforces the need for institutionalized defense, economic, and diplomatic mechanisms that can outlast electoral cycles.
Ultimately, the future of the Indo-Pacific will not be shaped by rhetoric or diplomatic communiqués, but by the willingness of capable middle powers to shoulder responsibility, project credibility, and prepare for contingencies now widely regarded as plausible. Japan and the Philippines have done more than signal intent—they are building facts on the ground, at sea, and in the policy frameworks that will define the coming decade.
In a region where the rules are under siege and the risks are rising, the Japan–Philippines partnership offers not just a model, but a mandate: that middle powers need not wait for great powers to act, and that order, once imperiled, must be defended not in theory—but in practice.♦
Richard Javad Heydarian
Mr. Heydarian is a prominent Filipino academic, author, and media commentator recognized for his extensive work on Asian geopolitics, Philippine politics, and populism. He holds academic positions, including currently serving as a senior lecturer at the University of the Philippines Asian Center and previously as a Professorial Chairholder at the Polytechnic University of the Philippines. Heydarian is a prolific writer, contributing to numerous international publications such as The New York Times, The Guardian, and Foreign Affairs, and has authored several books, including The Rise of Duterte: A Populist Revolt against Elite Democracy and The Indo-Pacific: Trump, China, and the New Global Struggle for Mastery. Frequently sought for his insights, he also appears as a political analyst for various media outlets and contributes to leading global think tanks.
Notes