Southeast Asia is watching the US-Israel conflict with Iran — and quietly drawing conclusions. Most countries have adopted a policy of non-interference, but behind the cautious and neutral stances, they are accelerating efforts to reduce their defense dependence on Washington.

The recent US-Indonesia defense agreement, followed by an apparent rift between the Indonesian defense and foreign ministries over granting the US overflight rights above the Strait of Malacca, resulting in a hold on access, clearly illustrates this tension.

President Trump's unpredictable, transactional foreign policy has widened the divide between Washington and many Southeast Asian capitals. Eroding trust and diminishing alignment are increasingly visible, while US disengagement from Association of Southeast Asian Nations (ASEAN) multilateralism signals a diminishing role in the region.

Though suggestions of a diminished US role in the region have circulated for some time, they have not always been backed by concrete evidence or outcomes. Successive administrations managed to reassert engagement after periods of drift. Those were seen in the "Pivot to Asia" under Barack Obama, the Indo-Pacific strategy during the first Trump administration and its continuation under Joe Biden.

At present, however, US influence appears to be declining more markedly. One key and visible indicator is the absence of unequivocal support from allies and partners during the ongoing Middle East crisis. Even traditionally friendly countries have voiced criticism of the US's war against Iran.

For instance, Singapore Foreign Minister Vivian Balakrishnan stated in late March: "I was surprised by the onset of hostilities. I did not think it was necessary. I do not think it is helpful. Even now, there are doubts about legality. For 80 years, the US underwrote a system of globalization based on UN Charter principles, multilateralism, territorial integrity, and sovereign equality. It led to an unprecedented period of global prosperity and peace."

Another important indicator is the ISEAS-Yusof Ishak Institute's State of Southeast Asia 2026 survey. Unsurprisingly, regional attitudes toward China and the US have shifted in recent years.

According to the survey, 52% of respondents now favor alignment with China, compared to 48% who still prefer the US. While the overall margin is narrow, the finding is nonetheless noteworthy: China is now perceived as more closely aligned with the interests of ASEAN member states than the US.