When US leadership loses its sheen

Over the past decade, Southeast Asia has tried to live with a difficult but workable strategic reality: while China was the region’s dominant economic force, the US remained a key security counterweight and ASEAN provided enough diplomatic space for its members to avoid being forced into binary choices. The State of Southeast Asia 2026 Survey suggests this balance is becoming harder to maintain. While the region is not turning away from Washington, it is becoming less assured by the direction of US leadership.

This shift is not dramatic enough to suggest a rupture, nor uniform enough to indicate a clear regional realignment. However, across a range of indicators — from geopolitical concerns and perceptions of US economic and political-strategic influence to Washington’s leadership on free trade and the rules-based order, assessments of the trajectory of bilateral relations and trust — the US’ broader standing in the region has weakened. This matters because Southeast Asia’s long-standing balancing strategy has depended not just on the continued presence of the US, but on the assumption that Washington still offers a degree of assurance, economic weight and normative leadership. These are qualities which China has traditionally been seen as offering to a lesser degree. All of them appear to be less secure.

Across the eight geopolitical issues surveyed, US leadership under President Donald Trump now ranks as Southeast Asia’s top geopolitical concern at 51.9 per cent, overtaking aggressive behaviour in the South China Sea at 48.2 per cent, which was the top concern last year (Figure 1). Concerns over Trump’s leadership are especially high in Singapore (76.8 per cent) and Indonesia (67.8 per cent). This new preoccupation suggests that Southeast Asians are increasingly uneasy not only about Sino-US rivalry, but also about the wider consequences of a deterioration in US leadership, in particular the use of tariffs and trade measures, policy unpredictability and the weakening credibility of Washington’s long-term commitments. This shift is significant because the South China Sea dispute has been the region’s foremost concern. The fact that the dispute now sits behind concerns about US leadership shows that Washington is no longer seen only as a stabilising counterweight.