Could a distracted US cast Asia Pacific allies adrift?

For Asia Pacific governments, the US–Israeli war against Iran is a reminder that conflicts in the Middle East do not stay in the Middle East. Since February 2026, oil has surged past US$120 a barrel, Terminal High Altitude Area Defense (THAAD) interceptors have reportedly been redeployed from South Korea to the Middle East and US President Donald Trump has publicly criticised regional allies for their lack of active support.

These concerns have historical precedent. Research on US military commitments in Iraq and Afghanistan between 2000–2020 finds that when Washington becomes consumed by major wars abroad, many authoritarian and hybrid regimes in the Asia Pacific drift diplomatically closer to China. For non-democracies, a distracted Washington reduces the likelihood of a coercive US response and lowers the cost of accepting what China pragmatically offers — trade, infrastructure and diplomatic cover. Democracies stay close to Washington, reflecting the residual power of shared political norms and long-term credibility commitments.

But the Iran war is also exposing new pressures which place the very foundations of democratic alignment into question.

Washington has undertaken its largest military buildup in the Middle East since 2003 and US allies in the Asia Pacific are openly concerned the redeployment of regional assets to the Gulf. Only months after US Defense Secretary Pete Hegseth told the 2025 Shangri-La Dialogue that ‘America is proud to be back in the Indo-Pacific — and we’re here to stay’, that commitment is being tested against the pull of another Middle Eastern war.

But unlike the open-ended ground wars of Iraq or Afghanistan that tied down US forces for years, the Iran campaign has been more limited in scope and is less likely to durably absorb US resources — though that could change if the conflict escalates into a ground commitment. Governments across the region are concerned not only with whether Washington is distracted, but also whether US priorities have become too volatile to sustain long-term alignment.

They are also watching what the US military can do. Carrier strike operations in the Gulf and long-range precision strikes on Iranian air defences are visible demonstrations of the kind of capabilities that matter in the Western Pacific. For some allies in the region, that display may reinforce rather than weaken US deterrence.

The economic fallout of conflict in the Middle East cuts in more than one direction. Disruption to oil flows through the Strait of Hormuz has hit Asia’s open economies hard , with consequences arriving within weeks, rather than the years it took for the post-9/11 wars to reshape alignments. The energy shock is also increasing Russian energy revenues , strengthening Moscow’s fiscal position during its war in Ukraine. This matters for Asia Pacific alignment because research shows diplomatic drift towards Russia also occurs when the United States is constrained, particularly among non-democracies.

China complicates the comparison further. Authoritarian and hybrid regimes moved diplomatically towards Beijing when the United States was tied down in Iraq and Afghanistan, but Beijing has so far behaved cautiously. Despite its ties with Tehran, China has limited itself to calls for a ceasefire, warnings against regional spillover and the evacuation of its nationals, while avoiding major military or economic commitments. As the Gulf’s single largest oil customer, Beijing has strong reasons to avoid a wider crisis. The conflict is also showcasing forms of US military reach that China still cannot easily match.

But Beijing’s restraint does not automatically reinforce US advantage. For some governments in the region, a cautious China may look like the more predictable partner . The question is whether that restraint will hold if the war drags on and US attention looks more permanently diverted.

Regional responses have been mixed. Democratic US allies — Japan, Australia, South Korea and New Zealand — have backed a March 2026 joint statement supporting freedom of through the Strait of Hormuz, even as some have expressed reservations the scale of the campaign. In Southeast Asia, where many states occupy the democratic middle ground, reactions have been more varied. Thailand has negotiated a separate deal with Iran for safe passage of its oil tankers through the Strait of Hormuz, placing it among countries Tehran deems ‘friendly’ alongside China, India and Russia. Malaysia and Brunei have gone further, strongly condemning the US–Israeli strikes.

It is too early to say whether these responses reflect a regime-based divide or if they are driven more by energy exposure and geographic proximity to the conflict. While past wars in the Middle East remain a useful guide to how US preoccupation can reshape alignment, this crisis is not a simple replay of Iraq or Afghanistan. The economic shock has hit faster, China’s response has been more cautious and the campaign’s limited nature sends a different signal US power.

Sustaining Asia Pacific alliances during this war requires going beyond military presence to demonstrating that US commitments to the region are institutional, not discretionary. But a deeper question rises over the foundations of democratic alignment itself. Established democracies stayed close to Washington over the past two decades partly because of shared political norms and the belief that US commitments were rooted in institutions rather than each administration’s priorities. That perception is harder to sustain today.

If democratic partners begin to doubt the anchor , the pattern that has held for two decades — democracies staying close to Washington while autocracies drift — may not survive this war.

Ha Eun Choi is Postdoctoral Research Associate in the Department of Politics and Public Administration, University of Potsdam.

Scott de Marchi is Professor of Political Science and Director of the Decision Science Program, Duke University.

Max Gallop is Senior Lecturer (Associate Professor) in the Department of Government and Public Policy, University of Strathclyde.

Shahryar Minhas is Associate Professor in the Department of Political Science and the Social Science Data Analytics Program, Michigan State University.

This article is adapted from the authors’ research article, ‘ Decisive or Distracted: The Effects of United States Constraint on Security Networks ’, published in the British Journal of Political Science.