The resurgence of the Monroe Doctrine: The US returns to its (expanded) hemispheric base

The history of the United States has oscillated between isolationism and interventionism, not at the whim of its presidents, but as dictated by geopolitical imperatives. This movement between extremes has many intermediate stages. Today we are witnessing a retreat that is neither complete nor isolationist: Washington is leaving other places, but plans to strengthen its presence in the Indo-Pacific to keep a close eye on China there; it is retreating to its side of the ocean, but is not entrenching itself behind its borders, instead confirming its willingness to interfere in the nearby hemispheric environment.

This is due to geopolitical constraints, even though Donald Trump's personality certainly accentuates and adds drama to some of these dynamics, which can be summarized in the following points:

1. There is no longer an enemy advancing across the planet. The supreme geopolitical imperative of the US is to prevent another superpower from being in a position to cross the oceanic divide separating North America from Europe or Asia and attack its territory. When countries expanded across those continents (Germany and Japan) and sought to use that territorial expansion as a base from which to attack the United States, Washington went to war. Then the USSR, an even more formidable enemy, redoubled the threat from both ends of Eurasia, and so the US sought allies: it helped its Western partners to prosper economically, guaranteeing international rules, in exchange for them lending their territories, as well as their political and military support, to counter Soviet pressure. The Bretton Woods system was also 'America First'.

2. No need for allies. The fall of the USSR ended the urgency of the Soviet threat, but it has been the war in Ukraine that has demonstrated with facts that Russia is no longer a superpower: it can scratch Europe's eastern flank, but it does not have the strength to invade Western Europe and use it as a staging ground to corner the US. Without a global enemy, the United States is abandoning its extensive military deployment, ceasing to safeguard the international system that underpinned that framework, and no longer bothering to look after partners it no longer needs.

3. The threat posed by China is of a different nature. If China remains within its current borders and, above all, does not cross the chain of islands that separate it from the open ocean, the risk to the US remains lower than that posed by the USSR. With India on one side and Japan/South Korea and Southeast Asia on the other acting as counterweights to China's expansionism, purpose is to provide military resources in the Indo-Pacific so that Beijing remains constrained in its regional projection. For the US, China's rivalry is different in nature from that posed by the USSR: it is not one of geographical positioning, as was the case then, facilitated by the ideological alliances of the Cold War, but rather one of technological dispute.

4. Expanding its base in its own hemisphere. In its rivalry with the other superpower, this time the game is not about advancing positions across the globe, but rather about strengthening its own base, both by expanding it and by preventing China from entering it (or removing it from some spaces it has already penetrated). In its retreat to the Western Hemisphere, the US seeks control of routes, supply chains, strategic mineral production, and nearshoring that complements US industry... while denying all of this to China or Russia (as seen with Venezuelan oil, which Washington does not need, but which it now deprives its rivals of). The novelty with respect to previous formulations of the Monroe Doctrine is that the United States is no longer satisfied with control of its traditional "backyard"—the Greater Caribbean—but is now looking north as well as south: to Canada and Greenland. The progressive melting of the Arctic makes what was previously Closed geopolitical dispute competitive: the American territories between the 49th parallel (the border between the US and Canada) and the pole become a place susceptible to rival infiltration and a presumed bridgehead for an enemy attack. The United States, which is already geographically in the middle of North America, also occupies the center of this expanded space between the North Pole and the equator.

5. Trump's acumen and intuition. Donald Trump has the ability, whether we want to admit it or not, to intuitively sense the shifting tectonic plates of geopolitics. His attitude, however, accelerates this seismic movement and exacerbates it. The same is true of Putin: realizing Russia's decline and the threat to its security posed by a disobedient Ukraine does not justify the invasion of its neighbor, which he should have won over by friendly and seductive means. Trump, too, should curry favor with surrounding nations and his other partners with a cooperative spirit, without the acrimony (and, of course, without the tariff aggression or military threats) with which he treats his interlocutors. However, we live in a time when powers pursue their national interests in a ruthless manner: the political and social polarization we see today in almost all countries is also evident in the international order.

6. At least until 2050. The dynamics described here will probably continue for at least a few decades, as they respond to fundamental developments that, although influenced by the personalities of their main protagonists, have their own trajectory. It is possible that, as the century progresses, China will become a rival to the United States with such extensive territorial control that it will replicate the danger posed by the USSR. To counter this, Washington would then once again require the support of close allies, reviving its multilateral involvement. But it is more likely that the rivalry with Beijing will not involve the domination of strategic territories, which would push the US to repeat or strengthen alliances for the control of geographical areas, but rather a struggle for nuclear, cyber, and satellite capabilities. In that case, the 'geo' in geopolitics would shift from the earth's surface to its digital and orbital envelope; what would matter then would be which platform is available, and the US hopes to have secured its hemispheric base.

A DOCTRINE THAT REVIVES EVERY CENTURY: 1823, 1904, 2025

The Monroe Doctrine responds to a need of the United States—the absence of threats in its area and that explains its survival as a doctrine, with different emphases at different times. It is named after the country's fifth president, James Monroe (1817-1825), although it was formulated by John Quincy Adams, who was his secretary of state and succeeded him as president (1825-1829). Proclaimed in 1823, at a time when the Spanish republics were gaining their independence, it served as a warning to the European powers to refrain from attempting to revive their old colonialism in the American continent. At the end of the Napoleonic Wars, the restoration of the monarchy was underway in much of Europe, and the United States feared that its neighboring republics, due to their weakness, could become a platform from which to attack it. Not long before, in 1812, British troops had reached Washington and burned the White House and the Capitol.

The statement, contained in Monroe's address to the first session of congress 18th congress S congress on December 2, 1823, stated:

“The occasion has been deemed propitious to affirm, as a principle in which the rights and interests of the United States are at stake, that the American continents, by virtue of the free and independent status they have assumed and maintain, should not henceforth be considered as subjects of future colonization by any European power (...) Therefore, due to the frankness and friendly relations existing between the United States and those powers, we declare that we will consider any attempt on their part to extend their system to any part of this hemisphere as dangerous to our peace and security."

In reality, the United States was not in a position to enforce that warning (France ignored it when it promoted the Second Mexican Empire). It would not be until the end of the century, when it had completed its Manifest Destiny and already had its current borders (after attacking Mexico, despite the doctrine's call to respect the sovereignty of the American republics), that it emerged as a power and began to project power in its surroundings. In 1898, it expelled Spain from Cuba and Puerto Rico (the doctrine had also committed to respecting those possessions), and in 1903, it brought about the breakup of Colombia for the construction of the Panama Canal, in a business that buried England's aspirations for tutelage in the region.

In this context of expansionism and interference, the Monroe Doctrine was reformulated with the so-called 'Roosevelt Corollary' of 1904. The 'America for Americans' that summed up the spirit of the early 19th century came to be conceived at the beginning of the 20th century as America (still understood as the entire continent) 'for Americans'. What had originally been more of a defensive stance by the nascent federation of thirteen colonies against the European metropolises now became an offensive attitude, typical of a power that was beginning to demand a place in the world, as evidenced by the Great White Fleet that Roosevelt sent out to sea in 1907, with which the US began to look beyond its shores.

Faced with evidence of the dysfunction of the Latin American republics, which was emboldening Europeans to send their gunboats to demand payment of outstanding debts (the final episode was the naval blockade of Venezuela in 1903, led mainly by England and Germany), Roosevelt proclaimed his corollary to the Monroe Doctrine. It was in his annual message to congress on December 6, 1904:

Chronic misconduct, or impotence resulting in a general weakening of the bonds of civilized society, may require in America, as elsewhere, the intervention written request some civilized nation as written request last written request , and in the Western Hemisphere, the adherence of the United States to the Monroe Doctrine may compel us, albeit reluctantly, in flagrant cases of such misconduct or impotence, to exercise international police power."

This 'corollary' —the term reference letter something that "can be easily deduced from what has been previously demonstrated," according to the RAE; something that is, therefore, a consequence, inference, or deduction—gave rise between 1912 and 1934 to US intervention in much of the Caribbean (Haiti, Dominican Republic, Nicaragua), where the US Army arrived with the excuse of 'building nations' but left behind 'police forces'.

Having dominated the region, the United States no longer needed to deploy new military forces there. Although interference continued, in alternating cycles of lesser and greater pressure (Franklin Roosevelt's Good Neighbor policy was followed by Eisenhower's coup d'état in Guatemala in 1954; Kennedy's Alliance for Progress was followed by Nixon-Kissinger's National Security Doctrine; the pacification that came with Carter's submission the Canal was broken by Reagan's use of the Contras in Nicaragua as proxies), the truth is that the United States' rise to the status of global superpower shifted Washington's interest to almost the entire world, reducing the intensity of its focus on its own hemisphere.

This overreach on the part of the United States had its oversights, such as the early Soviet presence in Cuba. Overconfident during the unipolar moment at the end of the Cold War and obsessed with the global war on Islamic terrorism after 2001, the US underestimated China's gradual penetration of the Americas, which has accelerated in the last two decades.

The Trump Corollary

While there were already signs during Trump's first presidency of how the new international era we are entering was beginning to take shape, the New York tycoon's return to the White House in 2025 has marked an official return to the Monroe Doctrine, now no longer looking at the threat from England/France (1823) or the skill England/Germany (1904), but at the rise of China. US support for Latin American military dictatorships in the 1960s and 1970s was also a manifestation of the Monroe Doctrine, this time against the USSR, but as the United States' fight against communism was global, this manifestation was not strictly hemispheric—which is probably why there was no update of the famous doctrine at the time—even though this anti-communism had its own characteristics in Latin America.

The Trump administration's renewed interest in the Western Hemisphere was first dubbed by analysts as 'Monroe Doctrine 2.0' and then as 'Donroe Doctrine', in a play on words that Donald Trump has made his own. In any case, official documents have accurately presented it as the 'Trump Corollary to the Monroe Doctrine'. This is stated in the National Security Strategy of November 2025 and in the Pentagon's implementation of this strategy in its National Defense Strategy of January 2026.

The first of these two documents, the National Security Strategy, expressly defines what this new corollary consists of:

We want to ensure that the Western Hemisphere remains reasonably stable and sufficiently well governed to prevent and discourage mass migration to the United States; we want a Hemisphere whose governments cooperate with us against narco-terrorists, cartels, and other transnational criminal organizations; we want a Hemisphere free from hostile foreign incursions or ownership of core topic assets, and that supports crucial supply chains; and we want to ensure our continued access to strategic core topic locations. In other words, we will assert and enforce a ‘Trump Corollary’ to the Monroe Doctrine” (p.5).

“After years of withdrawal, the United States will reaffirm and apply the Monroe Doctrine to restore American preeminence in the Western Hemisphere and protect our national territory and our access to core topic geographies core topic the region. We will deny non-hemispheric competitors the ability to position forces or other threatening capabilities, or to own or control strategically vital assets in our hemisphere. This ‘Trump Corollary’ to the Monroe Doctrine is a sensible and forceful restoration of American power and priorities, consistent with U.S. security interests” (p.15).

This last paragraph is reproduced in full in the second document, the National Defense Strategy, although with a few words changed to make its message even more forceful. The term "preeminence" is replaced by "military dominance," and it is stated that this will be "used" for national protection and "access to core topic territory core topic the region."

This text from the Pentagon, now renamed department War, says that Trump began his second term in "one of the most dangerous security environments" in US history. On the domestic front, "U.S. borders were overwhelmed, narco-terrorists and other enemies grew more powerful throughout the Western Hemisphere, and U.S. access to core topic territories core topic the Panama Canal and Greenland was increasingly in doubt."

Although the accredited specialization Panama Canal and Greenland had already been widely discussed by the Trump administration, its appearance in this official document is significant, especially with regard to the large island in the Arctic Circle, as it is formally included in the perimeter of the Western Hemisphere and is thus affected by the new version of the Monroe Doctrine. Greenland has certainly always been part of the hemisphere, but it has never been seen as part of the Americas, nor do we imagine its silhouette when we think of North America.

Corollary updates

The reformulation of the Monroe Doctrine at the beginning of the 21st century therefore introduces some new elements with respect to previous versions: the original from the early 19th century, which gave its name to this famous doctrine, and the adaptation made at the beginning of the 20th century, known as the Roosevelt Corollary.

Each one, logically, is the result of its historical context and obeys the geopolitical priorities of the United States at each time. In 1823, the US was eager to ensure the consolidation of its national viability and wanted to keep European powers away from any effort to prevent its own territorial expansion in the center of North America. In 1904, the US wanted to secure dominance over the Greater Caribbean, which, thanks to the Panama Canal connecting its two coasts, would establish its regional hegemony and catapult it to world power status. The era of the United States as a global superpower during the Cold War was marked by the National Security Doctrine which, as we have noted, can be seen as an adaptation of the Monroe Doctrine for that moment in time, but the very fact that it was not invoked as such highlights the reality that the confrontation with the USSR and communism was global and not limited to Latin America.

With this global military presence now unnecessary, because Russia has shown in Ukraine that it is no longer a superpower (and China does not pose the same geopolitical threat, as it does not threaten to have a continental platform from which it could one day cross the ocean and attack its rival; it can launch nuclear missiles, but that could also happen from a smaller country with sufficient capacity), the United States is retreating to its own hemisphere.

In the new world order of fragmentation that is being built on the ruins of the recent era of globalization, Washington wants to secure the natural resources of its hemisphere (and, of course, prevent other international contenders from accessing them). With interoceanic supply chains under threat, the US has an interest in preserving those that connect it to its geographical surroundings, where it has opportunities for offshoring thanks to cheaper labor.

The novelty with respect to the Monroe Doctrine of the previous two centuries does not lie so much in this economic exploitation, which has historically already occurred (the United Fruit Company and other fruit companies waged their 'banana wars'; Standard Oil was fundamental in the development of Venezuelan oil wells; Ford exploited rubber in the Brazilian Amazon), but rather in two other aspects: presenting the neighborhood itself as a direct threat (illegal immigration, drug trafficking, organized crime, narco-terrorism), which supports the arguments to justify even military action in that geographical environment, and the extension of the territorial scope of application of the doctrine, which includes Greenland and, therefore, also includes Canada.

Backyard, front yard

The Monroe Doctrine first emerged supposedly in defense of the sovereignty of the newly independent Hispanic republics, warning of their extreme political weakness (1823), and then justified the United States acting as a 'policeman', with the right to intervene, to correct the economic misgovernment of those same southern neighbors (1904): Washington claimed that both situations could attract European powers, which could then interfere with US interests. Today, interference from external rivals continues to be invoked, but Latin American countries themselves are also accused of harboring native threats that attack the US, not because of their governments' decisions, but precisely because of their inveterate misgovernment. In its first weeks, the second Trump administration designated several Mexican cartels and organized crime groups, such as Mara Salvatrucha and Tren de Aragua, as foreign terrorist organizations; it then reinforced its policy of deporting illegal immigrants, mainly Latin Americans, and took military positions in the Caribbean to combat drug trafficking. Trump has threatened to attack his neighbors (this has happened with Venezuela, and his accusations have been directed very directly at Mexico and Colombia) to resolve this external pressure.

If Russia's defeat in Ukraine means that Russia loses its status as a superpower and that the US is therefore no longer required, as in the second half of the 20th century, to deploy forces to counter its threat, the melting of the Arctic introduces another highly significant geopolitical variable. Since its emergence as a regional hegemon and superpower, the US has seen itself as a large island: the wide oceans to the east and west separated it from its rivals; the polar cold neutralized the northernmost part of North America, concentrating the Canadian population on the border with the US and making it highly dependent on that country; the desert in the south and Mexico's institutional weakness dehydrated any possible southern threat.

We have seen how the southern border is now perceived as a risk, and the same is beginning to happen with the northern border. With the Arctic opening up to navigation, Greenland is a candidate to become a bridgehead for a rival, introducing an element of vulnerability for the US in its 'high north'. As it gains relevance, Greenland ceases to be an appendix of the Western Hemisphere and becomes fully integrated into it. When people used to talk about the Americas, they never thought of Greenland: today it is another territory and is on its way to being classified as a substantial part of North America.

As long as Washington insists on looking toward the pole, Canada will become increasingly subsumed into the triangle formed by the 48 states of the US south of the Canadian border; its issue state, Alaska (elevated to that status only about sixty years ago); and Greenland (which Trump would also like to incorporate). Canada may resist pressure to become a mere federated entity (in reality, fragmented, if that were to happen) within the Union, but the development maritime routes that may occur in the future in the Arctic, through the Canadian islands, heralds US interference that Ottawa will have to deal with: a process that could be perceived, in a way, as the "Latin Americanization" of Canada. If the Greater Caribbean (the Gulf of Mexico, the Caribbean, and all its coastal states, including those of Central and South America, up to the equator) has been the traditional Yankee 'backyard,' a 'front yard' is now emerging in the Greater Arctic. In this space, between the pole and the equator, the US occupies the central strip: it is in the middle, as the center from which to directly command what constitutes a full quarter of the globe.

Trump's return to the Monroe Doctrine marks, in a way, the end of a 200-year cycle. After initially claiming the Western Hemisphere as its own geographical sphere of influence, the United States expanded its power throughout the world to counter threats originating in the Eastern Hemisphere. With the defeat of the USSR and after a period as the sole superpower, the US is returning to its hemispheric base from which to confront its new rival. The standoff with China is not about taking positions—physical spaces—on the planet (it is not, therefore, 'geo'-political in the strict sense), but rather technological, and for that Washington needs to secure what it has in its own continental environment: natural resources (strategic minerals, energy sources) and the benefits of 'nearshoring', both in terms of control of these nearby supply chains and trade routes and in terms of advantageous production. In a world where globalization is breaking down and the major powers will have to secure an area of direct influence, this hemispheric base could make all the difference.

Emili J. Blasco is director GASS and of the Applied Geopolitics program in the International Degree the University of Navarra.

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* The text does not consider the anecdotal case of 'Technocracy', whose map is reproduced here only because it coincides with the geographical area that the analysis considers to be of particular interest to the US. The Canadian network CBC published an article in 2021 comparing that movement with the government of tech moguls that sometimes seems to be advocated from Silicon Valley.