The first year of U.S. President Donald Trump’s foreign policy in Southeast Asia has been demonstrably mixed. On the one hand, Trump unexpectedly strengthened U.S. multilateral engagement by working with the Association of Southeast Asian Nations (ASEAN). His administration also deepened key bilateral relationships with the Philippines, Vietnam, and Indonesia—and even sought improved ties with Cambodia, despite its record as a serial human rights abuser. On the other hand, these achievements have been significantly offset by the long shadow of Trump’s highly unpopular tariffs on the region’s exports to the United States.
More broadly, Trump’s transactionalism—though it can be a helpful asset in Southeast Asia at times—also jeopardizes Washington’s long-term influence in the region. With his trademark unpredictability and volatility, Trump has fueled confusion, frustration, and a growing distrust of U.S. intentions. These concerns were reinforced on Jan. 3, when Trump launched a military raid to forcibly oust Venezuelan President Nicolás Maduro—prompting Singapore, a close and reliable U.S. partner—to note that it was “gravely concerned” about the preservation of international law. Moreover, the release of Trump’s new U.S. National Security Strategy last month barely even mentions Southeast Asia. The document frames the region largely as a vehicle for advancing U.S. economic objectives rather than as a strategic partner in its own right.
It is precisely this type of cold-blooded realism—one that openly treats Southeast Asia as a means toward the end of greater U.S. power—that risks creating a significant strategic rift in the region. Some countries, mostly authoritarian or semi-authoritarian, have welcomed Trump’s approach because they have long been suspicious of Washington’s motives and now see it as more transparent about its nationalist and selfish priorities. Others, however—including U.S. allies and close partners whose security depends on a sustained and predictable U.S. commitment to deter China—are increasingly uneasy. These states are more likely to seek strategic alternatives, whether with China, Russia, or various power configurations involving Japan, Australia, India, South Korea, the European Union, or the United Kingdom.
The bottom line is that because Southeast Asia can no longer fully count on the United States as a reliable great-power counterweight to China, the next several years are likely to witness a gradual rewiring of regional partnerships. Traditional U.S. friends may cultivate closer ties with China, while countries historically aligned with Beijing may find a new strategic outlet in Washington that allows them to escape overdependence on China. The net effect will be greater strategic ambiguity within ASEAN, particularly when negotiating sensitive sovereignty disputes such as those over the South China Sea.
One area of intense focus for the Trump administration is maintaining the integrity and security of commercial shipping lanes. The NSS, for example, argued that a Chinese attack on Taiwan would be devastating to U.S. national interests in part because the island “provides direct access to the Second Island Chain and splits Northeast and Southeast Asia into two distinct theaters.” Rather than emphasizing the geopolitical or human consequences of such an attack, the document underscored that “[g]iven that one-third of global shipping passes annually through the South China Sea, this has major implications for the U.S. economy.”
This blunt framing is likely unnerving to ASEAN members pushing back against China’s expansive maritime claims. While sustained U.S. attention to the South China Sea is welcome in principle, the motivations behind it matter. If Washington is patrolling the region primarily for its own economic interests, then how do the interests of regional states—especially treaty allies—factor into U.S. decision-making? What if U.S. economic interests change, perhaps due to accelerated decoupling from or engagement with China?
The Philippines provides a stark test case. Under an “America First” foreign policy, one could argue that it is not inherently in Washington’s interest to help Manila defend its exclusive economic zone against Beijing’s intrusions. Instead, the Philippines should shoulder that burden itself. Taken to its logical conclusion, this approach raises serious questions about whether the United States would support Manila if a shooting war erupted over contested features such as Second Thomas Shoal or Scarborough Shoal.
To be sure, Philippine President Ferdinand Marcos Jr. had a successful meeting with Trump at the White House in July, and U.S. Defense Secretary Pete Hegseth later announced the creation of a Task Force Philippines to strengthen maritime security cooperation to deter China. Still, it remains unclear how high defending the Philippines under the two countries’ mutual defense treaty ranks among Trump’s priorities, especially when weighed against competing economic and political considerations, including his desire for a grand economic bargain with Beijing.
Vietnam faces similar concerns, though without the protection of a formal security treaty with the United States. In 2023, Hanoi elevated ties with Washington, then under the Biden administration, to “comprehensive strategic”—the highest status in Vietnam’s official diplomatic hierarchy, on par with China and Russia. That move was intended, in part, to further enmesh U.S. and Vietnamese interests, including in the South China Sea. Yet Washington’s narrowly defined priorities under Trump suggest it may be less willing to support Vietnam’s defense of its maritime claims if doing so does not clearly advance U.S. interests.
Beyond maritime security, Trump has devoted growing attention to securing supplies of critical minerals. During the ASEAN summit in Kuala Lumpur in October, his administration signed mineral agreements with Cambodia, Malaysia, and Thailand. During bilateral trade negotiations with Indonesia, U.S. officials reportedly expressed strong interest in securing access to Jakarta’s vast reserves of nickel, cobalt, manganese, and copper—resources critical to U.S. industrial supply chains and to reducing Chinese dominance.
In a more controversial wrinkle, the Trump administration has also shown interest in Myanmar’s rare earth minerals—the world’s third-largest producer—despite the country’s ongoing civil war. Options reportedly under consideration include engaging both the military junta under Senior Gen. Min Aung Hlaing and rebel organizations such as the Kachin Independence Army, potentially trading sanctions relief for resource access. Although progress has been limited, the episode underscores the extent to which transactional logic is reshaping U.S. regional engagement.
Supply chains related to artificial intelligence represent another focal point. Last month, the administration announced a new initiative dubbed “Pax Silica” that aims to secure the supply chains for silicon and other critical minerals that are essential for advanced semiconductor manufacturing. Notably, the rollout named only one Southeast Asian country—Singapore—as a key partner, alongside U.S. allies Australia, Japan, and South Korea, with Taiwan included as a guest. The exclusion of most of Southeast Asia raises yet more questions about which countries Washington deems strategically valuable—and which it does not.
In some respects, this fixation on access, routes, and resources is not new. Past U.S. administrations pursued similar objectives but typically did so with greater subtlety and with an accompanying emphasis on alliances, partnerships, and values. The Trump administration has departed sharply from that approach, openly signaling that unless Southeast Asian states can demonstrate clear strategic benefit to the United States, Washington feels no obligation to sustain engagement. As the new National Security Strategy bluntly stated, “The days of the United States propping up the entire world order like Atlas are over.”
Put differently, Trump’s near-exclusive emphasis on a narrow conception of national interest over values or even broader strategic goals could make the United States behave more like China. Beijing’s own transactionalism—“pragmatism,” as Chinese leaders prefer to call it—has paid dividends in Southeast Asia, where many governments appreciate China’s aversion to lecturing on democracy or human rights. But it is far more difficult for the United States to pull off the same approach, given its historical role since World War II as the leader of the liberal, rules-based international order.
Nor is Washington likely to pull it off well. The United States is not China, and Southeast Asia does not expect it to behave as such. For decades, Washington’s influence in the region has rested not only on power and access, but on reassurance—on the belief that U.S. commitments, while imperfect, were ultimately durable, predictable, and rooted in something beyond narrow gain. By discarding that foundation in favor of explicit transactionalism, the Trump administration risks eroding the very advantages that have distinguished the United States from its chief strategic competitor.
Southeast Asian states are pragmatic, not sentimental. If U.S. engagement is reduced to a balance sheet—shipping lanes protected here, minerals extracted there—then regional governments will respond in kind, diversifying partners, diluting U.S. leverage, and hedging ever more aggressively toward China. Over time, this will not yield greater U.S. influence, but less: a region less willing to align, less confident in U.S. resolve, and less inclined to take risks on Washington’s behalf.
In seeking to escape the burden of leadership, the United States may ultimately discover that it has surrendered its greatest strategic asset in Southeast Asia—the trust that once made Washington’s power not just formidable, but preferable across much of the region.