Forging Resilience: How US–Japan Alliance Shapes Indo-Pacific Security And Deterrence – OpEd

In 2025, the United States–Japan security alliance is central to Indo-Pacific strategic competition, influencing regional power dynamics through a blend of deterrence, military collaboration, economic coordination, and diplomatic efforts.

This essay argues that the alliance not only counters China’s growing influence but also enhances regional stability by utilizing military force, strategic postures, coordinated technological investments, and multilateral partnerships. This metrics analysis shows how the US–Japan partnership has become an indispensable element in maintaining equilibrium amid the unpredictability of China and North Korea, as well as emerging transnational threats. It examines trends in defense expenditure, joint frequency exercises, economic resilience indicators, and diplomatic outreach.

Since 2015, Japan’s defense budget has increased by an average of 3.8% annually, reaching a record allocation of ¥68 trillion (approximately USD 63 billion) in fiscal year 2025. This funding aims to modernize Japan’s Self-Defense Forces and enhance integration with American military structures and command. Simultaneously, the United States has maintained approximately 50,000 service members in Japan, including rotational deployments of F-35 squadrons and Aegis-equipped destroyers in the East China Sea. In the first quarter of 2025 alone, the two countries conducted five large-scale exercises—an increase of 25% compared to 2024—simulating island-defense scenarios around the Ryukyu archipelago and joint air-defense drills in Okinawa. These robust military postures have significantly raised the threshold for unilateral coercion. According to analysis from the Japan Institute of International Affairs, China would need to deploy at least a 40% larger amphibious fleet to overcome the combined US-Japan naval assets in Taiwan, effectively imposing a prohibitive cost on Beijing’s military planners.

Beyond economic power, technological cooperation has emerged as a significant strategic battleground. In 2023, the CHIPS Act allocated USD 52 billion to domestic semiconductor manufacturing, prompting Japanese firms such as TSMC and Mitsubishi Electric to commit over USD 18 billion to joint ventures by early 2025. This public-private synergy has strengthened allied resilience: semiconductor export data shows that Japan and the US now account for 62% of the world’s advanced logic chip production capacity, up from 48% in 2020. This shift reduces the risk of supply chain disruptions that China could exploit. Collaborative R&D in dual-use technologies—including quantum hypersonic encryption defense algorithms, AI, and advanced maritime surveillance—has accelerated, with over 30 trilateral projects currently underway under the US-Japan Shared Initiative Research. The economic interdependence established by these initiatives makes it difficult for Beijing to use trade coercive practices without causing harm to critical allied infrastructure.

The alliance has effectively expanded its reach through multilateral integration. The revitalized Quad framework’s quarterly meeting in 2024 now includes coordinated maritime domain awareness efforts, which have mapped 87% of the South China Sea’s seabed—a 30% increase since 2022, facilitating safer navigation for commercial ASEAN vessels. Additionally, Japan and the US have jointly provided security assistance to Pacific Island nations, dispatching over USD 200 million for port development and coast guard training programs through 2025. These initiatives serve a dual purpose: deterring malign influence from external actors and reinforcing the norm of security cooperation under international law. Quantitative indicators highlight this success: the number of bilateral and multilateral agreements signed by Pacific Island governments with Washington and Tokyo increased from 12 in 2022 to 22 in 2025. This shift indicates a move towards collective capacity-building rather than zero-sum strategic alignments.

Nevertheless, the alliance, however, faces significant risks and inherent limitations. China’s rapid naval shipbuilding program is projected to produce 450 vessels by the end of 2025, while the combined total for the United States and Japan is only 360. This situation necessitates that qualitative advantages consistently compensate for numerical disparities.

Additionally, domestic political fluctuations in both democracies introduce uncertainties: the 2025 Japanese general election saw parties challenging the scope of collective defense, while debates in the United States Congress over defense authorization threatened to cap funding for adjustments to overseas force posture. Public opinion surveys conducted in March 2025 revealed that while 68% of Japanese citizens support the principle of the US–Japan alliance, only 43% endorse further increases in host funding for US forces, highlighting potential friction points. Additionally, Korea’s resumption of long-range missile testing—six launches in the first quarter of 2025—has strained alliance coordination resources, necessitating a reallocation of Indo-Pacific contingency planning towards homeland defense measures.

Addressing these challenges requires adaptive strategies that enhance credibility while maintaining domestic consensus. First, the United States, Japan, and other institutionalized countries should establish a mechanism for automatic budget realignment in response to emerging threats, ensuring that fiscal constraints do not undermine deterrence. Second, expanding “all-domain” interoperability—especially in cybersecurity situational awareness—will help counter China’s quantitative advantage at sea. Third, the alliance should deepen its engagement with Southeast Asian partners through tiered multilateral frameworks that enable ASEAN to participate in joint exercises aligned with their capabilities and threat perceptions. Finally, strategically enhancing communications by linking transparent alliance activities to regional economic benefits, such as job creation in host-nation communities and broader trade stability, can bolster support and protect against domestic politicization.

In integrating these measures, the US–Japan alliance will not only preserve its central role in deterring aggression but also evolve into a more inclusive, resilient foundation for the Indo-Pacific. By aligning defense modernization, technological cooperation, and multilateral diplomacy, adaptive governance mechanisms, the partnership can sustain a favorable balance of power in 2025 and beyond, delivering stability, prosperity, and rule rule-based order upon which regional and global interests converge.

The opinions expressed in this article are the author’s own.

References

• Blankenship, Brian. The Burden-Sharing Dilemma: Coercive Diplomacy in U.S. Alliance Politics. Ithaca: Cornell University Press, 2023. 
• RAND Corporation. The U.S.-Japan Alliance in an Era of Strategic Competition: Proceedings of the Twenty-Second U.S.–Japan Security and Defense Forum. Santa Monica, CA: RAND Corporation, November 29, 2023. 
• Baru, Sanjaya, ed. The Importance of Shinzo Abe: India, Japan, and the Indo-Pacific. New Delhi: HarperCollins India, July 2023.