Southeast Asia in 2025
In this brief, the author reviews select developments of a year that reshaped Southeast Asia’s strategic and economic landscape. These include Malaysia’s high profile ASEAN Chairmanship; the regional impact of the US’s “reciprocal tariffs”; developments in troubled Myanmar; the simmering Thailand-Cambodia border conflict; and the outlook for the Philippines, which holds the ASEAN Chair in 2026.
During the year, Malaysia hosted the largest ever ASEAN summit, which expanded ASEAN’s external engagement with the GCC and the wider Global South. However, ASEAN’s enduring institutional limitations were also on display, with its failure to impact developments in Myanmar and inability to resolve the Thailand-Cambodia conflict.
After initially promising to stay united in the face of “reciprocal tariffs” imposed by the US, ASEAN countries proceeded to conclude uneasy bilateral trade pacts with the US. While the future of these deals still hangs in balance, unilateral trade pressures from the US catalysed ASEAN diversification towards partners such as China, India, and the EU.
In Myanmar, where ASEAN was unable to exert pressure on Myanmar’s military, China showed its influence by helping the military regime to consolidate its position, as it commented an election process that is designed to preserve the military’s dominant position in Myanmar politics.
In the Philippines, President Ferdinand Marcos Jr. survived a challenging year in domestic politics, while garnering global attention for his strong stance against China’s aggressive actions in the South China Sea. The Philippines reached out to like-minded regional players as security partners, including India, but it remains to be seen if it can leverage its position as ASEAN Chair for 2026 to address pressing regional security challenges.
Finally, the author examines the nature and origins of the Thailand-Cambodia border conflict, which re-erupted in 2025 and remained substantially unresolved into the new year.
2025 was a particularly dynamic year for Southeast Asia in terms of the intensity of regional developments. Multilateralism, once the cornerstone of ASEAN’s identity, now appears weakened in both legitimacy and efficacy, as member states prioritise bilateral alignments and hedging strategies over collective action.
To read this DPG Policy Brief Vol. XI, Issue 6, please click "Southeast Asia in 2025”.
