What Southeast Asia Should Expect from Trump in 2026

In the first year of Trump’s presidency, there were some highs and lows in Southeast Asia. Based on this record, what should the region expect from Trump in 2026?

First, Trump’s attendance at the ASEAN Summit in October in Malaysia was a notable and welcome surprise. He was directly engaged in brokering a ceasefire between Cambodia and Thailand, presiding over a peace deal-signing ceremony in Kuala Lumpur. The second Trump administration has also strengthened defence and security ties with partners such as Indonesia, the Philippines and Vietnam. It has even improved relations with Cambodia, despite its record as a serial human rights abuser. On the economic front, Washington has signed critical minerals agreements with Cambodia, Malaysia, and Thailand, and agreed to negotiate reciprocal tariff reductions with these three countries and Vietnam.

These successes, however, were significantly offset by the long shadow of Trump’s highly unpopular reciprocal tariffs imposed across the region. More broadly, Trump’s trademark unpredictability and transactionalism have fuelled confusion, frustration, and growing distrust of US intentions. These concerns are reinforced by Trump’s newly released National Security Strategy (NSS), which only sparingly references Southeast Asia and frames the region largely as a vehicle for advancing American economic objectives.

If 2026 mirrors 2025, the administration risks remaining stuck in neutral at best, or accelerating the erosion of US influence at worst. This will create further openings for China.

Trump may attend the ASEAN summit hosted by the Philippines in 2026, but this is far from guaranteed. A key variable is personal incentive. Ahead of this year’s summit, Trump reportedly threatened to skip the event unless he was allowed to preside over the Cambodia–Thailand peace ceremony, which he sought to bolster his Nobel Peace Prize prospects. US-China relations also loom large. With Trump pursuing détente with Xi Jinping and planning a visit to Beijing in April, he may avoid steps — such as backing Manila’s push for a more hardline approach to China in the South China Sea — that could disrupt the momentum.

Beyond ASEAN, multilateral frameworks involving US participation endured in 2025. The Quad is explicitly endorsed in the new NSS as a means to prevent regional domination by a single power. However, Trump skipped the planned India-hosted summit, raising doubts about its trajectory. He also reaffirmed support for the trilateral Australia-UK-US (AUKUS) deal during Australian Prime Minister Anthony Albanese’s October visit, underscoring continued backing for Australia’s expanded military role in the Indo-Pacific, including Southeast Asia.

At the bilateral level, Trump has thus far maintained mostly cordial ties. Philippine President Ferdinand Marcos Jr. — one of America’s two treaty allies in the region — visited the White House in July 2025. The meeting was widely seen as successful, though Trump raised US tariffs on Philippine exports from 17 to 19 per cent. War Secretary Pete Hegseth later announced the creation of “Task Force Philippines” to strengthen maritime security cooperation aimed at deterring China. Still, questions remain about how high defending the Philippines under the Mutual Defense Treaty ranks on Trump’s priorities. His pursuit of improved relations with Xi suggests a deliberate effort to avoid disruptions, including involvement in disputes in an area the new NSS implicitly defines as China’s sphere of influence.

… concerns are reinforced by Trump’s newly released National Security Strategy (NSS), which only sparingly references Southeast Asia and frames the region largely as a vehicle for advancing American economic objectives.

Trump’s relationship with Vietnam has been more uneven. Hegseth’s November visit to Hanoi produced a new agreement on sensitive war legacy issues, including Agent Orange cleanup, unexploded ordnance removal, and accounting for missing personnel. Yet Vietnam continues to face steep US tariffs — 20 per cent overall, potential transshipment penalties of 40 per cent, and sectoral tariffs of up to 50 per cent. This has prompted Hanoi to hedge by deepening ties with China and diversifying partnerships, including towards the Middle East. As a result, Washington’s engagement with Vietnam may be subject to further setbacks and an erosion of hard-earned bilateral trust.

With Jakarta, Trump has used Indonesian President Prabowo Subianto’s language on closer economic and security cooperation, particularly on critical minerals and defence modernisation, including possible F-15 sales. In practice, however, relations appear strained, with a trade deal reportedly unravelling amid US accusations that Jakarta is backtracking. Meanwhile, Trump has surprised Malaysia. Despite Prime Minister Anwar Ibrahim’s vocal support for Hamas, Trump has prioritised access to critical minerals and transactional diplomacy, including presiding over the signing of the Cambodia–Thailand peace agreement. Still, US tariffs on Malaysian exports remain high at 19 per cent, though Trump has signaled possible selective reductions.

Perhaps the brightest spot in Trump’s Southeast Asia policy is Cambodia. The administration has revived Angkor Sentinel drills, pursued a US Navy visit to the Ream naval base, struck a critical minerals deal, and eased some tariffs. Trump also brokered a Cambodia–Thailand peace deal, though renewed clashes and tariff threats towards Bangkok risk undermining it. Also of concern is the fact that Trump’s relations with Bangkok have almost exclusively been based on threatening tariffs for violations of the peace deal with Cambodia — a heavy-handed way to treat a longstanding friend.

Another wrinkle is Trump’s reported interest in Myanmar’s rare earth minerals — the world’s third-largest supply — despite the ongoing civil war. Options under consideration allegedly include backing the Kachin Independence Army and engaging the junta led by Min Aung Hlaing, potentially trading sanctions relief for access, though progress remains limited.

Trump has also elevated Singapore by naming it — alongside key allies Australia, Japan, and South Korea — a member of “Pax Silica.” This strategic initiative is aimed at building secure and resilient supply chains while leveraging critical minerals to support the development of artificial intelligence. Beyond that, relations with Singapore, as well as Brunei, Laos and Timor-Leste remain relatively muted, leaving unclear what Trump has planned for them in 2026. It is possible that none of them are considered a priority in helping Washington counter China, or that Trump simply has not yet come around to dealing with them. This could all change quickly — for example, if Laos is receptive to a critical minerals deal with the US.

Overall, Trump’s Southeast Asia policy shows notable wins, but persistent concerns remain over the durability of tariff deals and his unpredictability — and whether ASEAN members can truly rely on his engagement. These uncertainties are likely to shape regional dynamics well into the new year.

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