ASPI Releases Landmark Report Warning That the U.S.–Japan Alliance Is Under Strain Amid Rising Indo-Pacific Threats

The Asia Society Policy Institute (ASPI) has released a major new report evaluating the resilience of the U.S.–Japan alliance under President Donald Trump’s second term, warning that the partnership faces mounting political turbulence at precisely the moment regional threats are accelerating.

Authored by Emma Chanlett-Avery, ASPI’s Director for Political-Security Affairs, “A Stress Test for Resilience: Risks and Opportunities for the U.S.-Japan Alliance” provides one of the most detailed assessments to date of how the alliance is adapting — and in some areas faltering — as geopolitical challenges intensify across the Indo-Pacific.

Tariffs and Political Friction Shake the Alliance

Chanlett-Avery writes that “the return of Donald Trump to the White House has profoundly strained the U.S.-Japan relationship.”Despite a productive opening to 2025, the imposition of steep U.S. tariffs on Japanese goods introduced sudden fractures that threatened to spill over into core security cooperation.

This political turbulence coincides with what the report characterizes as an exponential rise in regional threats. China, North Korea, and Russia are described as increasingly aligned in their strategic objectives and as deepening defense coordination — an axis that places new pressure on Japan's security architecture and U.S. commitments.

Working-Level Trust Persists, but Leadership Alignment Is Lacking

While operational cooperation between the two countries remains strong, the report warns that the alliance cannot rely solely on working-level relationships. The absence of sustained leader-to-leader alignment risks leaving major initiatives stalled and raises questions about U.S. credibility among Indo-Pacific partners.

“Without leader-level agreement and assurance on security commitments, buttressed by cabinet-level ministerial decisions that outline specific priorities, alliance initiatives will languish,” Chanlett-Avery writes.

This dynamic has taken on heightened significance following the new Takaichi administration in Japan, which is seeking clarity and consistency from Washington at a time of unprecedented regional volatility.

Recommendations for Rebuilding Momentum and Stability

To restore strategic momentum and prevent further erosion of confidence, the report lays out a comprehensive set of policy recommendations aimed at building a durable, mutually beneficial framework for cooperation.

These include:

• Reforming burden-sharing formulas to reflect evolving security responsibilities;

• Regularizing leader-level and ministerial-level dialogues, ensuring predictability and transparency;

• Accelerating command-and-control integration, a critical step for effective joint operations;

• Reshaping extended deterrence engagement, particularly in the nuclear and missile defense domains;

• Leveraging calibrated pressure to encourage Japan’s expanding security capabilities;

• Supporting greater Japanese leadership across the Indo-Pacific;

• And broadening domestic U.S. support for the alliance, which the report notes has narrowed amid shifting political winds.

These proposals aim to serve both nations’ interests without introducing new instability into a region already confronting unprecedented strategic realignment.

A Region in Flux and an Alliance at a Crossroads

Chanlett-Avery concludes that, despite political frictions and intensifying regional dangers, the logic underpinning the alliance remains unwavering.

“The threats are urgent and growing, the politics are swinging wildly, but the rationale for a robust U.S.-Japan alliance is as strong as it ever has been.”

As Washington recalibrates its global strategy and Tokyo accelerates its security reforms, the U.S.–Japan alliance now faces a defining test: whether it can maintain coherence and trust in an era of heightened geopolitical volatility — or whether political dissonance at the top will undermine one of the Indo-Pacific’s most essential stabilizing pillars.