American expansionism under Donald Trump

Historical context and the Donroe Doctrine

The United States had not acquired new sovereign territory since entering into political union with the Northern Mariana Islands in 1986, marking the end of a long period of continental and overseas expansion. President Donald Trump's expressed desires to acquire territory, beginning during his first term and intensifying in his second, represent a significant departure from recent decades of U.S. foreign policy which relied on alliances, bases, and economic influence rather than annexation. The administration framed this shift as a necessary assertion of American power, with Deputy Chief of Staff Stephen Miller stating the U.S. would 'conduct ourselves as a superpower' under Trump. This expansionist mentality was formally articulated in the 2025 National Security Strategy as the 'Trump Corollary' to the Monroe Doctrine, informally known as the Donroe Doctrine.

It explicitly treats the Western Hemisphere as a U.S. sphere of influence where American security interests justify intervention and territorial ambition. Secretary of State Marco Rubio defended the policy by arguing that the European Union has no right to define how the United States operates its national security. Public opinion within the U.S. has shown limited appetite for this agenda, with a February 2025 YouGov poll finding only 4% of Americans supported expansion if it required force, while 48% opposed expansion altogether. The doctrine's application has involved both rhetorical claims and concrete actions, setting a new tone for American engagement with its neighbours and the world.

Ambitions in North America

Trump's expansionist rhetoric has consistently included Canada, though the proposed methods have varied. Upon retaking office in 2025, he began tying an agenda of aggressive trade tariffs to the broader idea of U.S. annexation of Canada, citing grievances over fentanyl smuggling and migrant flows. This economic coercion sparked a Buy Canadian movement in Central Canada and tourism boycotts of the U.S. in Eastern Canada. While Trump has ruled out using military force against Canada, he has repeatedly called for Canada to join the United States as a state, framing it against the backdrop of the ongoing trade dispute.

In August 2026, Trump signed an executive order renaming Lake Ontario as 'Lake America' within the U.S. Geographic Names Information System. This followed a similar action in January 2025, when he renamed the Gulf of Mexico the 'Gulf of America' in federal usage, applying the name from the U.S. shoreline to the seaward boundaries with Mexico and Cuba. These symbolic acts reinforced the administration's view of shared continental geography as falling under American purview. The renaming of the Gulf was first proposed in a news conference and mentioned in Trump's inaugural address before being enacted by executive order on his first day back in office.

The campaign for Greenland

The desire to acquire Greenland has been a persistent theme of Trump's expansionism, first stated in 2019 and vigorously pursued from the start of his second term. In December 2024, Trump described ownership and control of the island as an absolute necessity for national security, building on a prior offer refused by the Danish Field. Administration figures, including then Vice President elect JD Vance, echoed that controlling Greenland was critical, stating there was 'a deal to be made'. Trump himself refused to rule out military or economic force to take over Greenland, telling NBC in May 2025, 'I don't rule it out... We need Greenland very badly.'

The campaign triggered a major diplomatic crisis with Denmark, described by a former foreign affairs official as 'historically unheard of'. In early 2025, the Danish government summoned the U.S. ambassador twice in response to reports of American intelligence gathering on Greenlandic independence sentiments and covert operations by U.S. citizens allegedly tied to Trump to foment secessionism. U.S. public support for the idea remained low, with a January 2025 USA Today poll showing only 11% supported purchase or annexation, and a January 2026 Quinnipiac poll finding 86% opposed using military force. Congressional allies introduced supporting legislation, including the Make Greenland Great Again Act to authorize acquisition and the Red, White, and Blueland Act which proposed renaming Greenland.

By January 2026, reporting indicated that President Trump had backed off his most urgent rhetoric regarding Greenland for the time being. This coincided with a new security agreement between the United States, Denmark, and Greenland. The agreement suggested expanded American rights in the region without a formal transfer of sovereignty. This outcome illustrated a historical pattern where the United States achieves strategic objectives through access and influence. It represents a shift from the formal expansionist practices of the 19th century.

Intervention and ambition in Latin America

The Trump administration's most direct application of expansionist policy occurred in Venezuela with Operation Absolute Resolve in 2026, a military intervention that removed President Nicolás Maduro from power. Following the operation, Trump stated the U.S. would 'run' Venezuela, though the government led by acting president Delcy Rodríguez remained in place and became far more amicable to American interests. This action was preceded by designating a Venezuelan gang as a terrorist organization and offering a large reward for Maduro's arrest, framing the intervention as a national security necessity. The administration's goal, as reported, was a regime change similar to the fall of the Assad regime in Syria.

Other Latin American nations were subject to threats and coercive rhetoric. Trump suggested Mexico should become a state, alleging the U.S. subsidized it, and formally renamed the adjacent gulf. He demanded Panama return control of the Panama Canal, citing excessive rates and Chinese influence, and did not rule out using military force to take it. Secretary of State Marco Rubio traveled to Panama to push for reclaiming the canal, and a subsequent joint security deal allowed for the potential stationing of American troops there. Trump also made threatening comments about Colombia's president and, during the 2026 Cuban crisis, stated he would have the 'honor of taking Cuba' in some form.

Mechanisms and justifications

The Trump administration employed a multi faceted approach to advance its expansionist goals, blending legislative proposals, executive actions, military intervention, and economic pressure. In Congress, allies introduced bills like the Panama Canal Repurchase Act to provide a legal framework for acquisition. Executive orders were used to unilaterally rename international waters like the Gulf of Mexico and Lake Ontario, asserting symbolic American dominion. Military force was deployed in Venezuela, and its potential use was consistently hinted at for other targets like Greenland and the Panama Canal. Economic pressure, in the form of threatened tariffs, was also a tool, as seen with the Arctic Endurance operation countries and in trade disputes with Canada.

The primary public justifications centred on national security and economic interests. Controlling Greenland and the Panama Canal was framed as critical for security against geopolitical rivals, with particular emphasis on countering Chinese influence in Panama. The administration invoked the history of American manifest destiny and the Monroe Doctrine to argue for a renewed hemispheric dominance. Officials like Secretary Rubio argued the U.S. was merely operating as a superpower should, responding to threats and defending its interests. Economic arguments were also used, such as claiming the U.S. subsidized Mexico or that Panama charged excessive canal tolls, to justify demands for control or integration.

Domestic and international reactions

Internationally, the expansionist comments drew widespread criticism from politicians outside the U.S. and caused significant diplomatic strains, most notably with Denmark over Greenland. The campaign also alarmed Indigenous communities, with reports noting concern over rising American imperialism threatening Indigenous sovereignty abroad and at home. Within the United States, the Democratic Party introduced bills aimed at preventing the administration from invading countries without congressional approval, signalling political opposition. The Democratic legislation was a direct response to the administration's aggressive foreign policy posture and its threats of military action.

In Canada, the rhetoric and associated trade policies provoked a tangible public backlash. The Buy Canadian movement gained traction in Central Canada, and Eastern Canada saw organized tourism boycotts of the United States. The '51st state' calls formed a contentious backdrop to the ongoing trade dispute, affecting the broader bilateral relationship. American public opinion polls consistently showed majority opposition to expansionist ventures, particularly those involving military force, indicating a disconnect between the administration's ambitions and popular support. This domestic opposition was a consistent feature throughout the period, from the early 2025 polling to the 2026 poll on Greenland.

Strategic shift and future implications

The evolution of the Greenland situation by early 2026, moving from explicit annexation demands to a security agreement, may signal a pragmatic shift in how the administration pursues its objectives. This aligns with a historical pattern where the U.S., as a dominant global power, has found it more effective to secure strategic goals through bases, alliances, and influence rather than formal annexation. The case of the Northern Mariana Islands, the last U.S. territorial acquisition, demonstrated that direct control is no longer necessary to project power. The U.S. approach to territorial expansion changed significantly over the 20th century as international borders became more fixed and respect for sovereignty grew.

Nevertheless, the stated ambitions and actions of Trump's second term have altered inter American relations. The revival of expansionist doctrine, the willingness to use military force for regime change aligned with territorial ambition, and the symbolic renaming of shared geography have reintroduced concepts of imperial prerogative into U.S. foreign policy. For neighbouring countries like Canada and Mexico, this has meant dealing with a relationship where their sovereignty is periodically questioned by rhetorical and economic pressure from a superpower reasserting a hemispheric sphere of influence. The long term effects of this period on diplomatic trust and regional stability remain to be fully seen, as the policies have created new tensions and uncertainties across the hemisphere.

Questions about American expansionism under Donald Trump

What does Donald Trump want to do with Canada?

President Trump has repeatedly called for Canada to join the United States as a state, often tying this idea to disputes over trade tariffs. He has cited issues like fentanyl smuggling and migrant flows as grievances, using economic coercion to pressure Canada. However, he has explicitly ruled out using military force against Canada. These calls have contributed to a Buy Canadian movement and tourism boycotts within Canada.

Why does Trump want Greenland?

Trump and his administration have consistently stated that controlling Greenland is an absolute necessity for United States national security. They view the island's geographic position as strategically vital. This desire led to a major diplomatic crisis with Denmark. It also involved intelligence gathering on Greenlandic politics and legislative proposals in the United States Congress to authorize its acquisition or rename it.

What are the Gulf of America and Lake America?

These are names instituted by President Trump through executive orders for shared international waters. In January 2025, he renamed the Gulf of Mexico the 'Gulf of America' for U.S. federal usage, applying it from the U.S. shoreline to the boundary with Mexico and Cuba. In August 2026, he similarly renamed Lake Ontario as 'Lake America' within the U.S. Geographic Names Information System. These were symbolic acts asserting American dominion.

How do Americans feel about Trump's expansionist ideas?

United States public opinion polls show limited support for territorial expansion, especially if it involves force. A February 2025 YouGov poll found only 4 percent of Americans supported expansion requiring force, while 48 percent opposed expansion altogether. A January 2026 Quinnipiac poll specifically on Greenland found 86 percent of American respondents opposed using military force to take it over. That same poll also found 55 percent opposed buying it.

What is the Donroe Doctrine?

The Donroe Doctrine is the informal name for the Trump administration's revival and corollary to the Monroe Doctrine. It was formally outlined in the 2025 National Security Strategy. The doctrine asserts the Western Hemisphere as a United States sphere of influence. It states that American security interests justify intervention, regime change, and territorial ambition there. The name is a portmanteau of 'Donald' and 'Monroe'.

Sources: Wikipedia and current public reporting, checked by the Nosy Mag desk. Last updated 2026-10-19.