Southeast Asia Influence Index: Trump administration policies likely to erode US influence in Southeast Asia
China leads the United States as the most influential partner to Southeast Asian countries, according to a new Lowy Institute data project. The United States’ inconsistent influence across the region will likely decline further due to the Trump administration’s foreign policies.
The Southeast Asia Influence Index — authored by the same team that produces the annual Lowy Institute Asia Power Index: Susannah Patton, Jack Sato and Rahman Yaacob — measures the relative importance of ten external partners to the eleven countries in Southeast Asia, based on their economic relationships, defence networks, cultural influence, diplomatic relationships, and regional engagement.
China is the most influential power in Southeast Asia and the leading partner for six out of eleven individual countries (Cambodia, Indonesia, Malaysia, Myanmar, Thailand, and Vietnam). The United States is the leading partner for just two countries: the Philippines and Singapore.
But the Index reveals that China does not dominate the region, as Southeast Asian countries collectively are more important to each other than any single external partner.
The United States is the second-most influential partner for the region, but its influence varies wildly country-to-country.
The authors argue this influence is likely to erode further due to the impacts of the Trump administration’s global policies, including tariffs, cuts to foreign aid, and restrictions on international student visas.
Lowy Institute Deputy Research Director Susannah Patton said the new research was an important addition to the Asia Power Index. While the Asia Power Index compares the power of countries throughout the Indo-Pacific, the Southeast Asia Influence Index zooms in on influence dynamics for each Southeast Asian country.
“Our research reveals the diversity and complexity of Southeast Asia’s international relationships. China leads the United States by a clear margin. But we also demonstrate the importance of neighbourhood relationships among Southeast Asian countries, which means that China has not drawn the region into an uncontested sphere of influence.”
OVERALL INFLUENCE
The top ten most influential countries in Southeast Asia, across five measures: Economic relationships, defence networks, diplomatic influence, cultural influence, and regional engagement.
1. China — 65.3
2. United States — 64.4
3. Japan — 47.9
4. Australia — 38.8
5. Malaysia — 36.6
6. Singapore — 35.7
7. Indonesia — 34.8
8. South Korea — 33.8
9. Thailand — 32.0
10. Vietnam — 29.7
KEY FINDINGS
- China is everywhere in Southeast Asia. China is a consistent presence across every Southeast Asian country. It is the region’s leading, but not dominant, external partner.
- America’s two faces. The United States is the second-most influential partner for the region, but its influence varies wildly. The Trump administration’s policies will further erode US influence in Southeast Asia.
- Southeast Asia’s collective dynamic. Collectively, Southeast Asian countries are more important to each other than to any external partner. Intra-regional dynamics, especially relations between direct neighbours, often matter more than competition among external powers.
- Japan leads the Indo-Pacific powers. Beyond the United States and China, four major Indo-pacific powers — Australia, India, Japan and South Korea — exercise influence in Southeast Asia. But only Japan has a multidimensional presence across the entire region.
- Long-distance relationships. Southeast Asia’s next tier of partners from outside the region — Canada, France, Russia, and the United Kingdom — are peripheral players. Yet when focused tightly on geographic or thematic areas of strength, these countries can exert sharp influence.
- Diversification with dependence. No Southeast Asian country is within the uncontested sphere of influence of a single external partner, but several countries are highly exposed to China in specific sectors, such as tourism, investment, or trade.
MEDIA CONTACT
Andrew Griffits
Head of Media and Communications
media@lowyinstitute.org