Trump’s territorial ambitions send tremors beyond the western hemisphere

In his first month back in the White House, US President Donald Trump has unleashed a torrent of aggressive rhetoric that has reawakened the spectre of America’s territorial conquest by coercive power. He has not ruled out the use of military force to seize Greenland and the Panama Canal, floated the audacious idea of “absorbing” Canada and signalled that he would “take over” the Gaza Strip as a “big real estate site”. These brazen statements – feints or truth – reignite historical memories about US imperialism, including in Southeast Asia, where the scars of its colonial rule and military interventions are still felt. Most alarmingly, Trump’s threats could potentially embolden the expansionist ambitions of bigger powers worldwide, threatening to unravel the principles of sovereignty and territorial integrity that have underpinned global stability for decades.

The history of US involvement in Southeast Asia has long reflected contradictory impulses. As a former colonial power in the Philippines, it imposed direct rule for half a century, leaving a legacy of deep-seated anti-American sentiments that still resonate today. Yet, Washington also sought to distance itself from European colonialism, presenting itself as a champion of decolonisation. US President Woodrow Wilson’s advocacy for the right to self-determination at the League of Nations in 1918 initially galvanised Southeast Asian anti-colonial movements, including Ho Chi Minh’s fight against French rule. After World War II, Washington pressured allies like the Netherlands to grant independence to Indonesia. Yet, when its Cold War interests prevailed, Washington selectively upheld colonial rule, backing France’s attempt to recolonise Vietnam and ultimately launching its own military intervention in the country.

This dual legacy continues to shape regional perceptions of the US. Anti-Americanism runs deep in the region, even for longstanding US allies and today’s American strategic partners like the Philippines and Vietnam. This is despite how in the decades following the Cold War (and for some maritime Southeast Asian states during the Cold War), the US was largely viewed as a security guarantor against communist expansion and potential regional hegemons.

Trump’s perceived expansionist designs against US neighbours and the Palestinian people will only deepen anti-American sentiments globally. This trajectory echoes the early 2000s, when the US’ wars in Iraq and Afghanistan, marked by unilateralism and disregard for international norms, fuelled widespread resentment. As Fareed Zakaria warned then, “anti-Americanism will become the global language of protest—the default ideology of opposition”.

In Southeast Asia, the US already endured significant reputational damage during Trump’s first term (2017-2020), which saw a brief recovery in the early years of the Biden administration, only to dip again in 2023, particularly due to its stance on the Gaza conflict. Trump’s extreme proposal to uproot Palestinians and “take over” Gaza will only deepen these resentments, further eroding trust and inflaming anti-Americanism across the Middle East and Southeast Asia, particularly among Muslim-majority nations like Indonesia, Malaysia, and Brunei.

Furthermore, for Southeast Asia, where small and larger states coexist and share borders with some great powers, the resurgence of “might makes right” and revanchism would be deeply unsettling, given festering historical grievances and unresolved territorial disputes among regional nations.

Borders between Southeast Asian countries were largely defined after World War II, and some remain contested to this day. The Philippines has never formally relinquished its claim over Sabah, while Malaysia, under then prime minister Mahathir Mohamad in 2020, challenged the 2008 International Court of Justice (ICJ) ruling that affirmed Singapore’s sovereignty over Pedra Branca. Even in countries where border demarcation is ongoing, historical grievances over past territorial losses persist — such as those that the Cambodians have towards Vietnam and Thailand.

While territorial conflicts and the “might makes right” mentality among Southeast Asian nations may seem like relics of the past, thanks to ASEAN’s tireless efforts in fostering regional amity and cooperation over decades, we must never take this hard-won stability for granted. As William Faulkner put it, “The past is never dead. It’s not even past.” Russia’s invasion of Ukraine serves as a stark warning. Now, when the US – the world’s most powerful nation and once the architect and guarantor of the international system grounded on the principle of sovereign equality – turns its back on that very same principle and returns to imperialist instincts, it will set a dangerous path, emboldening others to follow suit or double down their own expansionist ambitions.

The US in Trump’s image can no longer claim the moral high ground in resisting coercive actions by other larger powers against smaller neighbours for territorial gains. His administration’s approach to the Americas harks back to the nineteenth century Monroe Doctrine, which declared the Western Hemisphere as America’s exclusive domain. China’s territorial and maritime ambitions in the South China Sea echo that doctrine. Just as the US once asserted dominance across the Americas, China now seeks to consolidate its control over vast maritime spaces that overlap with Southeast Asian nations’ territories and exclusive economic zones.

In 2017, Trump outlined his Free and Open Indo-Pacific Vision as “a place where sovereign and independent nations, with diverse cultures and many different dreams, can all prosper side-by-side, and thrive in freedom and peace”. This now rings hollow. Southeast Asia, with its complex web of historical grievances and unresolved territorial disputes, stands at the crossroads of these perilous currents if Trump’s words become reality.

Hoang Thi Ha is Senior Fellow and Co-coordinator of the Regional Strategic and Political Studies Programme, ISEAS – Yusof Ishak Institute.

This article originally appeared on the ISEAS–Yusof Ishak Institute's Fulcrum on 18 February 2025.