The Cambodia-Thailand border conflict is characterized by recurring tensions over territorial demarcation and national sovereignty, particularly around the Preah Vihear temple and adjacent areas. This conflict continues to show the fragile nature of peace and regional order in mainland Southeast Asia. Although occasional armed skirmishes have given way to recent diplomatic exchanges, the dispute remains unresolved, deepens historical grievances, competes nationalist narratives, and limits existing conflict resolution mechanisms.Traditionally, such interstate disputes in Southeast Asia have been mediated through regional bodies like ASEAN, or adjudicated by international legal institutions such as the ICJ. However, the erosion of confidence in multilateral institutions, the paralysis of global governance mechanisms, and the growing polarization of international politics have challenged these conventional avenues for dispute settlement.

In this evolving geopolitical landscape, the role of global hegemons, particularly the US, in maintaining regional stability and deterring conflict demands renewed scrutiny. Within the framework of Hegemonic Stability Theory (HST), which posits that a dominant power is essential to the creation and preservation of international order, this article examines whether the foreign policy approach of US President Donald Trump offers an unconventional but potentially effective model for managing the Cambodia-Thailand border tensions. By analyzing Trump’s transactional and unilateral style of diplomacy through the theoretical lens of HST, this article explores the possibility that hegemonic leadership can still serve as a stabilizing force, even in an increasingly multipolar and fragmented international system. The article also opens a critical dialogue on whether power-based statecraft can succeed where institutional diplomacy struggles, particularly in the context of small state conflicts in contested geopolitical spaces.

HST argues that the maintenance of international order and the provision of global public goods, such as security, open markets, and stable currency regimes, require the leadership of a dominant power (Webb et.al, 1989). This hegemon, by its overwhelming capabilities and strategic interests, upholds the rules of the game, deters conflict, and manages systemic risks that could destabilize the international system. Historically, the US has played this role, particularly in the post-World War II liberal order, by strengthening multilateral institutions, protecting and promoting global trade, and providing security guarantees to allies and partners.

In this traditional model, border conflicts between smaller states, such as Cambodia and Thailand, have often been defused or managed through a combination of US-led diplomatic and economic pressure and strategic use of development assistance. The US has long leveraged its hegemonic influence and encouraged states to resolve disputes within institutional frameworks like the United Nations or ASEAN, while simultaneously offering economic and political incentives to deter escalation. However, the foreign policy orientation of Trump marks a significant departure from this established hegemonic model. Guided by the “America First” policy, Trump prioritizes a transactional, nationalist, and unilateral approach to international affairs. His administration withdrew from multilateral agreements, such as the Paris Climate Accord and the Trans-Pacific Partnership (TPP), disinvested in traditional alliance systems, and relied on coercive tools, including tariffs, sanctions, and political pressure, to advance US interests (O’Brien, 2024).

This hegemonic approach, coined as transactional hegemony, substitutes long-term normative commitments with short-term strategic bargaining (Flint, 2025). It reimagines the hegemon not as a steward of global public goods, but as a dominant player in a series of bilateral negotiations by using its power asymmetry to extract favorable outcomes. While critics argue that this undermines global stability and the rules-based order, it nonetheless demonstrates an alternative mode of hegemonic engagement that is pragmatic, flexible, and outcome-driven. In the context of regional disputes like the Cambodia-Thailand border conflict, this raises a few key questions: Can transactional hegemony serve as a functional mechanism for conflict management? Can a hegemon’s direct, coercive, or incentivized intervention succeed in stabilizing disputes that have proven resistant to multilateral mediation? The paper also explores how Trump’s foreign policy could be applied to this Southeast Asian conflict.

While Southeast Asia is not a consistent strategic priority for the Trump administration, the region nevertheless witnessed selective and highly visible forms of US engagement (Darmawan, 2025). These interactions, ranging from economic deals to diplomatic and military engagement, illustrate a distinctive pattern of hegemonic behavior. Rather than acting as a consistent rules-based mediator, the US under Trump positions itself as a strategic broker, intervening when and where US interests aligned with benefits for transactional and geopolitical gains.

Three key features define Trump’s approach to Southeast Asia. First, Trump deploys trade as a key instrument of statecraft, evidenced by intensified trade negotiations with Southeast Asian countries and reciprocal tariffs against China (Abalo, 2025). Although framed around rectifying trade imbalances, these measures also show to smaller states that access to the US market can be used as a bargaining chip in broader strategic negotiations. Second, through expanded the Freedom of Navigation Operations (FONOPs) in the South China Sea, Trump continues to challenge Chinese maritime claims and reassure regional states of continued US security interest (Gerval and Henderson, 2022). Third, the summits with North Korean leader Kim Jong-un, held in Singapore (2018) and Hanoi (2019), reflect Trump’s preference for personalized diplomacy. While these meetings produced limited substantive outcomes, they reinforced the image of the US as a disruptive but indispensable actor in Asia’s security architecture.

These examples point to a model of hegemonic engagement that is opportunistic and conditional. Rather than functioning as an impartial arbiter grounded in international law, the Trumpian hegemon seeks to increase leverage, be it economic, military or reputational, to extract compliance, secure deals, and deter instability.

In the context of the Cambodia-Thailand border conflict, this statecraft could theoretically assume several forms. First, the US could dispatch high-level envoys or special representatives to quietly mediate between Cambodia and Thailand by leveraging personal relationships and power asymmetries to craft face-saving compromises. Second, Washington might offer Cambodia and Thailand reciprocal tariff reduction or development assistance tied explicitly to de-escalation or compliance with agreed-upon border mechanisms. Third, in response to renewed military activity, the US could threaten targeted sanctions or publicly call out violation and place reputational and economic pressure on the offending party. Fourth, while Cambodia and Thailand maintain strategic ties with China, US mediation efforts in their border dispute suggest a challenge to Beijing’s regional influence. If China cannot effectively manage tensions in its own backyard, it raises broader questions about its capacity to project stable leadership in more distant arenas, including the Middle East.

While such strategies carry risks of perceived interference and neo-imperial overreach, they also offer a path for decisive US engagement where multilateral institutions have struggled to yield results. In this sense, Trump’s approach may hold unexpected relevance for managing the ongoing regional disputes, especially in contexts where conventional diplomacy has failed to generate momentum. The application of the Trumpian hegemonic statecraft to the Cambodia-Thailand conflict presents both strategic opportunities and significant constraints. A nuanced assessment shows that while aspects of Trump’s transactional diplomacy may resonate with regional political realities, they also risk undermining the legitimacy and sustainability of conflict resolution efforts.

There are three potential opportunities. First, Trump’s foreign policy is largely devoid of ideological constraints and favors transactional bargaining over value-based diplomacy (Flint, 2025). This pragmatism may align well with Southeast Asian political cultures, where elite bargaining and regime preservation, often take precedence over normative alignment (Vatikiotis, 1999). Regional leaders may see value in a hegemon that prioritizes deals over doctrines. Second, the strategic use of economic instruments, both incentives (e.g., reciprocal tariff agreements, investment flows) and punishments (e.g., targeted sanctions or aid withdrawal), offers an alternative to the slow pace of legal arbitration (Torn, 2025). For Cambodia and Thailand, this incentive-driven model could lower the political costs of compromise and avoid the rigidities and reputational risks associated with formal adjudication. Third, both Cambodia and Thailand maintain varying degrees of strategic partnership with the US. A high-profile US intervention could raise the international profile of both countries. This may be particularly attractive to governments seeking to balance Chinese influence or to elevate their geopolitical standing.

Conversely, there are four underlying limitations. First, Trump’s tenure was marked by a weakening of the US normative authority, particularly in areas related to democracy promotion, human rights, and multilateralism. This erosion compromises Washington’s ability to act as a trusted and impartial mediator. Regional actors may view US engagement as self-serving or unpredictable, reducing the credibility of any negotiated outcome. Second, Trump’s skepticism toward international law and institutions, risks devaluing mechanisms such as the ICJ. This could inadvertently encourage parties to pursue unilateralism or military posturing over legal arbitration and thus undermine peaceful norms of dispute settlement. Third, ASEAN’s diplomatic architecture is underpinned by the principles of non-interference, consensus, and quiet diplomacy. Trump’s approach stands in stark contrast to these. US intervention under this model could strain intra-ASEAN cohesion, provoke diplomatic backlash, or undermine regional ownership of the conflict resolution process. Finally, inconsistent or heavy-handed US engagement may create opportunities for China to deepen its influence. Beijing could position itself as a more predictable and regionally attuned partner, offering alternative mediation platforms, development assistance, or security guarantees. In this sense, Trump-style diplomacy could reinforce the strategic competition it seeks to counterbalance.

The potential application of the Trumpian hegemonic statecraft to the Cambodia-Thailand border conflict brings into sharp relief a foundational tension within HST: Is international order best sustained through shared norms and institutional frameworks, or through the coercive and strategic interventions of a dominant power? The Trump administration’s foreign policy illustrates a hegemon not as a guarantor of multilateral norms, but as a transactional enforcer who seeks outcomes through bargaining, leverage, and deal-making.

Moreover, this shift has profound implications for the architecture of regional order in Southeast Asia. Under Trump, the US largely abdicated its post-Cold War role as a norm entrepreneur and distances itself from liberal internationalist principles such as rule of law, institutional engagement, and support for international adjudication. Instead, its hegemonic posture became more instrumental and prioritizes tactical gains over long-term normative commitments. While such an approach may produce rapid de-escalation in the Cambodia-Thailand border dispute, it simultaneously weakens the structural foundations upon which small states have historically relied to safeguard their sovereignty.

In addition, for Cambodia in particular, a country that has actively engaged with international legal mechanisms including the ICJ to assert its territorial claims, this erosion of normative order is especially destabilizing. Without a hegemon committed to upholding legal principles and institutional dispute resolution, small and medium powers are left vulnerable to coercion, power asymmetries, and the unpredictability of great power competition. Trump’s hegemonic engagement, while effective in brokering short-term deals, offers no durable framework for norm internalization, peaceful dispute resolution, or regional integration.

In this sense, the Cambodia-Thailand case illustrates the broader trade-off between strategic negotiation and normative order. The Trumpian diplomacy may serve as a tactical tool in moments of immediate crisis, but it does little to contribute to a rules-based system where small states can expect fair treatment irrespective of power. As hegemonic behavior becomes increasingly transactional, the legitimacy and sustainability of the international order may erode and leave space for rival powers, informal spheres of influence, and renewed instability in contested borderlands.

Trump’s foreign policy presents an alternative model of hegemonic engagement. Grounded in coercive diplomacy, personal diplomacy, and bilateral bargaining, this style of statecraft emphasizes immediate strategic returns over long-term institutional investment. In the context of the Cambodia-Thailand border conflict, such an approach could offer short-term benefits by breaking diplomatic stalemates, incentivizing negotiations, and drawing high-level international attention to an otherwise neglected regional issue.

However, this model is not without costs. Trump-style interventions, while effective in halting escalation and incentivizing negotiations, are fundamentally transactional. They lack the normative foundations, such as adherence to international law, institutional continuity, and rule-based dispute resolution, that underpin stable and predictable international order. For small states like Cambodia, whose security often depends on legal norms and multilateral protections, the erosion of these foundations presents long-term strategic risks. Moreover, while Trump’s methods may manage conflict, they rarely transform relationships or resolve underlying structural tensions. This distinction is critical to any enduring theory of hegemonic stability. A truly stable order requires more than strategic bargains. It necessitates shared norms, predictable behavior, and institutional trust.

In short, while Trump’s transactional hegemony offers tactical value in navigating the Cambodia-Thailand tensions, it is insufficient as a basis for sustainable peace or regional order. The future of stability in Southeast Asia will depend not only on the presence of power, but on how that power is exercised, the rules-based structures that small states rely on for their sovereignty and security.

References

Abalo, Kodzovi. 2025. “A Critical assessment of Trump’s reciprocal tariff formula and a theory-based alternative.” Available at SSRN 5207232.

Darmawan, Aristyo Rizka. 2025. “How Trump’s foreign policy may hurt US interests in Southeast Asia.” Australian Institute of International Affairs. February 13. https://www.internationalaffairs.org.au/australianoutlook/how-trumps-foreign-policy-may-hurt-us-interests-in-southeast-asia/.

Flint, Colin. 2025. “Hegemonic retreat: Transactionalism as foreign policy.” The Geographical Journal. https://rgs-ibg.onlinelibrary.wiley.com/doi/epdf/10.1111/geoj.70007.

Gerval, Adam, and Mark Henderson. 2022. “US policy in the South China Sea across three administrations.” E-International Relations. https://www.e-ir.info/2022/06/27/us-policy-in-the-south-china-sea-across-three-administrations/.

O’Brien, Robert C. 2024. “The return of peace through strength: Making the case for Trump’s foreign policy.” Foreign Affairs, June 18. https://www.foreignaffairs.com/united-states/return-peace-strength-trump-obrien.

Torn, Chanritheara. 2025. “Cambodia urges Thailand to accept the ICJ’s jurisdiction,” Cambodianess, July 05. https://cambodianess.com/article/cambodia-urges-thailand-to-accept-the-icjs-jurisdiction

Vatikiotis, Michael RJ. 1997. “ASEAN 10: The political and cultural dimensions of Southeast Asian unity.” Southeast Asian Journal of Social Science: 77-88. https://www.jstor.org/stable/24492981.

Webb, Michael C., and Stephen D. Krasner. 1989. “Hegemonic stability theory: an empirical assessment.” Review of International Studies 15 (2): 183-198. https://www.jstor.org/stable/20097178.

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