Originally published by Pacific Forumthis article is reprinted with permission.
In almost half a year, Prime Minister Sanae Takaichi has postponed Japan’s defense policy in an unknown territory. The main defense budget FY2026 has REACHED ¥9.04 trillion (approximately $58 billion), with total security-related spending at approximately ¥10.6 trillion, in the district 1.9% of GDP.
The 2% threshold, long treated as sensitive, has effectively been reached ahead of schedule. At the LDP convention in April 2026, she Signaling that the constitutional review is inevitablewith a target proposal for 2027.
This is more than higher costs. It is a tense phase of military normalization under pressure. The driver is a China-Taiwan trilemma: Japan must contain China, prepare for instability around Taiwan, and guard against uncertainty in US commitments, all without provoking escalation or exhausting its capacity.
While a stronger military posture can increase deterrence and reassure the United States, rapid acceleration still creates inherent trade-offs, and prioritizing one target can weaken another in practice.
The pressing question is whether Japan can transform this accelerated growth into sustainable military capabilities before structural limits impose limits.
Acceleration beyond predecessors
Japan’s trajectory did not begin with Takaichi. Under long-serving Prime Minister Shinzo Abe, the outer limits of postwar security policy were expanded, notably through 2015 legislation that reinterpret Article 9 to allow limited collective self-defense.
Fumio Kishida, Prime Minister from 2021-2024, consolidated that trajectory, forcing Japan to reach 2% of GDP in defense spending by 2027 while revising core strategic documents.
Takaichi forced the execution under time pressure. Her supermajority term in February 2026 is allowed it to compress what had been a gradual process. The speed has reduced political resistance, but it has also limited the time available for institutions to absorb the changes.
March 2026 reorganization of the Self-Defense Forces reflects this shift. A Fleet Focused Surface Force focuses on naval command, while a new amphibious and mine warfare group emphasizes the focus on island defense. The Air Self-Defense Force has been expanded into an Air and Space Self-Defense Force.
Procurement has been accelerated, including Tomahawk acquisition and improvements in indigenous systems. There have been restrictions on arms exports FACILITATEsignaling a more active role in defense industrial cooperation.
The emphasis has gone beyond preparing for contingencies and towards shaping them. This transition brings initiative, but also greater exposure to miscalculations and institutional strain.
The China-Taiwan trilemma as a central driver
The strategic logic behind this acceleration is rooted in geography and time. China’s military modernization continues in scaleaccompanied by persistent gray area activity around the Senkaku Islands. At the same time, a Taiwan emergency, whether through blockade or direct force, has Behe a planning scenario and not a distant possibility.
Japan sits uncomfortably close to this potential flashpoint. The Nansei Islands (also called the Ryukyus) stretch toward Taiwan, with some points only about 110 kilometers (68 miles) away. Critical sea lanes passing through The Miyako Strait and Bashan Channel carry the vast majority of Japan’s energy imports. Disruption to these corridors would immediately register as an economic blow.
Tokyo increasingly treats Taiwan as strategically relevant but operationally limited.
Political gridlock and readiness gaps raises doubts about its ability to sustain a protracted defense. Japan cannot assume time or US availability will be on its side, especially under an administration that frames alliances in more transactional terms.
These pressures cannot be neatly reconciled. Strengthening prevention risks escalation. Preparing for a Taiwan emergency requires resources that strain resilience. Defending against US insecurity requires autonomy that can complicate coordination. The result is a managed tension rather than a balanced strategy.
Geographic focus and operational displacement
Japan’s response is most visible along its southwestern arc. The islands of Yonaguni, Ishigaki and Miyako are being strengthened with missile emplacements, surveillance systems and logistics infrastructure designed to support sustained operations. Forward armament and fuel points expand air coverage. Unmanned systems improve surveillance while reducing risk to personnel. Electronic warfare capabilities are intended to disrupt adversary targeting.
this “southwest wall” is a distributed network designed to complicate movement through The first island chain and increase operating costs. The emphasis is on denial—slowing down and limiting an opponent rather than defeating them outright.
From Beijing’s perspective, such a network complicates rapid austerity options, but does not eliminate them. Saturation tactics or blockade strategies can still impose strong pressure, especially if Japan struggles to sustain operations. Denial depends as much on consistency as on initial positioning.
Main constraints: Human resources, demographics and doctrinal legacy
Japan’s defense-building ambition faces structural limits that are harder to overcome than budget ceilings.
The most immediate is the workforce. At the end of FY2024, the Self-Defense Forces remained at 89.1% of authorized strength, with recruitment shortfalls continuing despite enhanced eligibility and retention measures. This gap already affects readiness.
A denial strategy built on distributed, high-speed operations throughout the southwestern islands is manpower intensive. It requires rotation, redundancy and the ability to absorb abrasion. Japan is weakest where its strategy requires it most.
Demographic trends reinforce this limitation. The pool of draft-age citizens continues to shrink, projected to decline by another 30% by the mid-2040s, while competition from the civilian labor market remains strong. Expanding the force will be difficult despite the increased budget.
Doctrine presents a different challenge. The longstanding emphasis on an exclusively defense-oriented policy under Article 9 it is increasingly disconnected from operational practice. Counterattack capabilities and force restructuring drive more flexible doctrine. Takaichi’s pushing because the constitutional review seeks to reconcile this gap, but the process remains politically sensitive.
Even when funding exists, the transformation into skills is uneven. It goes roughly ¥1 trillion into defense appropriations unspent each year due to procurement delays, industrial setbacks and currency effects. The constraint is no longer the willingness to spend, but the ability to sustain the capability over time. These pressures concentrate risk in long-duration operations, where initial gains are hardest to sustain.
Historical echoes as a cautionary limitation
Japan’s postwar identity continues to shape domestic debate and external perception. The legacy of World War II and the normative weight of pacifism remain embedded in political culture. They no longer function as a direct barrier, but define the limits of acceptable politics.
Public protests in April 2026, including a great demonstration off the diet and coordinated nationwide action, reflect ongoing concerns. Coalition dynamics reinforce the need for care. Younger voters appear more open for a stronger defensive stance, but this openness does not translate into unconditional support.
From abroad, China continues to frame Japan’s military developments through historical narratives, while other regional actors take it easy. Tokyo’s challenge is to signal restraint externally while expanding capability internally. Perception remains an integral part of prevention.
Future outlook: 2026–2035 inflection points
Future Revisions of Japan’s National Security Strategy will shape the next decade. Technology will play a bigger role, SPECIALLY in unmanned systems and AI-enabled support, providing partial relief from manpower constraints. Partnerships will be deepened, including with Philippines and Australia.
Several trajectories stand out. Prolonged gray area pressure in the East China Sea would do TRIAL operational sustainability, exposing weaknesses in personnel and logistics. Economic pressure from Chinacombined with fiscal constraints, may slow expansion. A successful one constitutional revision it can strengthen the alliance’s legal clarity and coordination, testing its internal cohesion.
Each path emphasizes a different dimension of Japan’s strategy—operational sustainability, fiscal sustainability, or political legitimacy. None can be managed by spending alone.
Realism must be matched with determination
Takaichi has provided what Japanese defense policy has long lacked: urgency backed by resources. The challenge has changed. It is no longer about overcoming political hesitations or breaking fiscal taboos.
Japan’s rearmament now depends on whether the country can sustain what it has chosen to start. The limitations it faces are permanent, not transitory. How they are managed will determine whether this acceleration produces sustainable military capacity or a force that expands quickly but struggles to endure when tested the most.
Tang Meng Set (mktang87@gmail.com) is a freelance analyst and commentator from Singapore. He graduated from S. Rajaratnam School of International Studies (RSIS), NTU, Singapore in 2025. By profession, Meng Kit works as an aerospace engineer. He has a keen interest in geopolitics and narrow issues.
