The Association of Southeast Asian Nations (ASEAN) is Southeast Asia's primary multilateral organization, an 11-member grouping of nations with a combined population of 684 million and a combined annual gross domestic product (GDP) of around $3.8 trillion in 2024, according to the ASEAN Statistics Division. Established in 1967, it has grown into one of the world's largest regional fora, representing a strategically important region straddling some of the world's busiest sea lanes, including in the Straits of Malacca and the South China Sea. Collectively, ASEAN ranks as the world's fifth-largest economy and the United States' fourth-largest export market.
ASEAN's members are Brunei, Burma (Myanmar), Cambodia, Indonesia, Laos, Malaysia, the Philippines, Singapore, Thailand, Timor-Leste, and Vietnam (see Figure 1). Timor-Leste, the region's newest country, was granted full membership in October 2025. Members rotate as chair: Malaysia was ASEAN's chair for 2025, and the Philippines assumed the chair for 2026. ASEAN engages in a range of diplomatic, economic, and security discussions through hundreds of annual meetings and through a secretariat in Jakarta, Indonesia.
ASEAN is a diverse and informal organization. Two of its core operating principles are consensual decisionmaking and noninterference in the internal affairs of its members. Some observers argue that this style constrains ASEAN from acting strongly and cohesively on important issues. Others argue that these principles—dubbed the "ASEAN Way"—promote regional stability and ensure that the group's members continue to discuss issues where their interests sometimes diverge, crediting ASEAN with fostering the peace and growth much of Southeast Asia has enjoyed for over 30 years. For instance, in 2011, ASEAN helped diffuse a localized but violent border dispute between Thailand and Cambodia, an issue that has flared again since June 2025. ASEAN's principles have been tested in recent years as the organization seeks to mediate the conflict between those two members and address the fallout from the Burmese military's 2021 coup d'état, which has led to a political and humanitarian crisis.
ASEAN and Asian Regional Architecture
Unlike the European Union (EU), ASEAN has no multilateral governing body, and many observers see Asia's economic and security institutions as underdeveloped. ASEAN convenes and administratively supports a number of regional fora, several of which include other governments (known as "dialogue partners"), including the United States. Since the 1980s, ASEAN has been critical in driving the formation of regional institutions, a role Southeast Asian governments call "ASEAN Centrality."
The ASEAN Regional Forum (ARF), first convened in 1994 with 26 Asian and Pacific states plus the EU, was formed to facilitate dialogue on political and security matters. The East Asia Summit (EAS), created in 2005, is an evolving, leaders-level forum with a varied agenda; the United States gained membership in 2010. The EAS includes all 11 ASEAN members, plus Australia, the People's Republic of China (PRC or China), India, Japan, New Zealand, Russia, South Korea, and the United States. The ASEAN Defense Ministers Meeting-Plus (ADMM+), established in 2010, regularly brings senior defense officials from EAS members together and hosts military exchanges.
Over the past decade, cooperation through non-ASEAN regional groupings such as the Quadrilateral Security Dialogue, the Australia-UK-U.S. (AUKUS) security partnership, and other "minilateral" groupings involving regional nations—including some ASEAN members—has deepened. Some Southeast Asian observers express concern that such cooperation weakens ASEAN's centrality, while others argue that multilateral integration fosters the interests of ASEAN members.
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Figure 1. ASEAN Members |
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Source: Graphic created by CRS. |
U.S.-ASEAN Relations
The United States has long-standing bilateral relations with individual Southeast Asian nations, including treaty alliances with the Philippines and Thailand and a close security partnership with Singapore. Many U.S. policymakers have seen engagement with ASEAN as complementing bilateral relationships and strengthening the region's collective diplomatic weight as other regional players gain in economic and military power. The United States initially supported ASEAN as a means to promote regional dialogue and as a bulwark against communism, becoming an ASEAN Dialogue Partner in 1977. In 2009, the United States acceded to the ASEAN Treaty of Amity and Cooperation and committed to an annual U.S.-ASEAN Meeting. In 2010, it opened the U.S. Mission to ASEAN in Jakarta and appointed the first resident ambassador in 2011. In 2012, the United States and ASEAN agreed to raise the level of the U.S.-ASEAN meeting to a Leaders Meeting. The relationship was elevated to a U.S.-ASEAN Strategic Partnership in 2015 and to a Comprehensive Strategic Partnership in 2022.
Past U.S. Administrations have identified numerous U.S. interests in Southeast Asia. Though the emphasis has varied between Administrations, these interests have included fostering democracy and human rights; encouraging liberal trade and investment regimes; addressing maritime security and tensions in the South China Sea; promoting environmental protection; countering piracy and terrorism; combatting human trafficking and trafficking in narcotics and wildlife; and addressing public health risks. Initiatives aimed at deepening ties with ASEAN have included U.S.-ASEAN Connect to coordinate U.S. public- and private-sector economic initiatives; a Smart Cities Partnership to promote U.S. investment in the region's digital infrastructure; an expanded Fulbright Exchange of ASEAN-U.S. Scholars; and the Young Southeast Asian Leaders Initiative (YSEALI), which offers scholarships and opportunities for young leaders.
The United States faces a range of challenges in engaging with ASEAN, including ASEAN's limited ability to address the coup in Burma, violence on the Thai-Cambodian border, regional concerns about the impact of growing Sino-U.S. tensions, the continued operation of scam centers in the region, and U.S. sanctions or other restrictions on member governments and their officials. While many Southeast Asian officials have welcomed U.S. efforts to push back against some PRC actions, many also are concerned that efforts to "contain" China could be counter-productive. U.S. support for Israel amidst the humanitarian crisis in Gaza also may affect U.S. diplomacy with some ASEAN members, especially Malaysia and Indonesia.
Some regional officials have expressed concern over the current trajectory of U.S. policy toward Southeast Asia under the Trump Administration. On April 2, 2025, the President levied some of the highest tariff rates in the world on ASEAN members; tariff rates currently vary widely, ranging from 10% (Singapore) to 40% (Laos, Burma). Many ASEAN members are dependent on manufacturing exports for economic growth and are deeply integrated in regional and global supply chains.
Historically, the United States has provided a range of assistance to ASEAN and its members. According to a 2024 State Department factsheet, between 2002 and 2024, the United States provided over $14.1 billion in economic, health, and security assistance and over $1.5 billion in humanitarian assistance to Southeast Asian nations. Following the restructuring of the U.S. Agency for International Development (USAID) under the State Department and the cancellation of numerous U.S. foreign assistance programs to Southeast Asia, some observers have questioned the reliability of the United States as a partner.
ASEAN, China, and the South China Sea
China is the largest trade partner and a major source of investment for many Southeast Asian nations. Concerns about China's growing influence in the region, use of economic leverage to achieve political and strategic goals, and efforts to exert control over much of the South China Sea have strained some ASEAN members' relations with China. ASEAN governments' different approaches to China also have led to tensions within the group.
Four ASEAN members—Brunei, Malaysia, the Philippines, and Vietnam—have maritime territorial disputes with China (as well as with each other), and others have interests in the South China Sea's natural resources and shipping lanes. In 2002, ASEAN and China agreed to a nonbinding Declaration on the Conduct of Parties in the South China Sea, in which they agreed to "resolve their territorial and jurisdictional disputes by peaceful means, without resorting to the threat or use of force" and to work toward the creation of a formal Code of Conduct to govern activities in the region. The Philippines has indicated a Code of Conduct will be a priority during its 2026 ASEAN chairmanship.
ASEAN's Economic Integration
ASEAN has an internal free trade agreement (the ASEAN FTA, or AFTA.) In 2015, the group launched an ASEAN Economic Community (AEC) to promote trade liberalization and regulatory harmonization among members, with the goal of creating a single ASEAN market and integrated manufacturing base. The ASEAN Digital Economy Framework Agreement (DEFA) is set to be concluded and signed in 2026, aimed at bolstering digital economy governance. ASEAN has trade agreements with several regional partners, including Australia, China, India, Japan, New Zealand, and South Korea. In 2020, ASEAN and five of those nations signed a trade agreement known as the Regional Comprehensive Economic Partnership (RCEP) (India withdrew). Four ASEAN nations—Brunei, Malaysia, Singapore, and Vietnam—are members of the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP). ASEAN members seek to promote infrastructure development, particularly in building greater regional "connectivity" through investment in transport and information technology. This has led to substantial demand for foreign investment, including in some cases through China's Belt and Road Initiative (BRI).
Human Rights and the Burma Crisis
Some Members of Congress—and some of ASEAN's members—have long voiced concerns about human rights conditions in several ASEAN member states. Some are effectively one-party states, and coups in Burma (2021) and Thailand (2006 and 2014) deposed democratically elected governments. ASEAN's approach to human rights violations among its members has become a touchstone issue following the coup and widening civil war in Burma. In 2021, ASEAN issued a five-point plan for resolving the crisis, but successive ASEAN envoys to Burma have had little success. Other human rights issues in ASEAN include the banning of the political opposition in Cambodia and continued efforts by Thailand to safeguard military authority through restrictions on civil rights.