The ‘Trump Corollary to the Monroe Doctrine’. An analysis by Elbridge Colby

Earlier this month, I represented the Department of War and the Secretary of War, Pete Hegseth, at the 17th Conference of Defence Ministers of the Americas (CDMA) in Cusco, Peru. There, I outlined what we believe to be a historic opportunity for the United States and its regional neighbours to work together, based on a realistic and pragmatic approach grounded in a well-understood common interest.

Much has changed in the Western hemisphere since the first CDMA meeting in 1995, at the height of the so-called ‘unipolar moment’. At that time, American and Western strategy was shaped by highly idealistic abstractions. A realistic vision grounded in geography and national interests took a back seat to liberal internationalism and the so-called ‘rules-based international order’. Three decades on, like it or not, that era is over. President Donald Trump and the Department of Defence are not merely acknowledging this: they are actively reshaping the strategy of the United States and its allies to address this new reality, following a flexible realism outlined in the 2025 National Security Strategy and the 2026 National Defence Strategy. This implies a fundamental shift in our approach to the Western Hemisphere – a necessary shift. For the past generation, the very hemisphere in which our country is situated has been a periphery in the American strategic imagination. To many right-thinking people, focusing US strategy and military forces on the Western Hemisphere and the problems of our region seemed petty, unworthy of our armed forces. But what was presented as benevolent disinterest has, in fact, turned into harmful disinterest.

In recent decades, the scourge of narco-terrorism in Latin America has worsened dramatically. A record number of American and Latin American citizens – hundreds of thousands in recent years – have died as a result of lethal drugs and the violence perpetrated by narco-terrorists. The far-left regimes that have supported these groups have proliferated, from Nicolás Maduro’s Venezuela to Daniel Ortega’s Nicaragua and Evo Morales’s Bolivia. These are governments that have failed in their own countries and exported that failure to ours, encouraging mass immigration. This has contributed to the worst border crisis in US history and has destabilised many of our societies. Under President Trump’s leadership, we view the Western Hemisphere differently. We view it through the lens of flexible realism, ‘America First’ and common sense. From this perspective, our hemisphere – particularly Central America, the Caribbean and northern South America – is essential to the security and prosperity of the American mainland and ordinary citizens.

The Department of Defence plays a central role in this new approach. But let us be clear: this is not a strategy in which everything is treated as a military problem. The Department operates as part of an integrated whole-of-government effort, in close collaboration with regional partners. At the same time, this approach signals that US military capabilities will be an integral part of the response to these lethal threats. We will not treat ISIS or al-Qa’ida in our hemisphere with kid gloves. Instead, we will deploy the full range of US tools, including the Armed Forces. This is demonstrated by Operation Southern Spear, through which the Department has gone on the offensive against narco-terrorist networks – not to replace other instruments of state power, but to reinforce them. We regard joint operations led by partner nations as force multipliers and as the way to achieve lasting results.

In Cusco, I explained how the intensification of our presence in the hemisphere forms part of a broader geopolitical and defence strategy. And I argued before our neighbours that the success of the new American strategy is also in their interests. We call this strategy the ‘Trump Corollary to the Monroe Doctrine’ – or, more simply, the ‘Donroe Doctrine’. The Trump Corollary states that the United States “will protect its territory and access to strategic areas in the region. We will prevent adversaries from deploying forces or other threatening capabilities in our hemisphere”. We know that the Monroe Doctrine remains controversial. But it is also often misunderstood. Our interpretation draws on the Monroe Doctrine in its original meaning: not a distorted version, but a principle aimed at strengthening, supporting and guaranteeing the independence, security and prosperity of the countries of Latin America and the Caribbean. This is what sets our approach apart. Our enlightened interest in the Western Hemisphere does not lie in the exploitation, subordination or dependence of our neighbours. On the contrary, the Trump Corollary is aimed at their success: greater prosperity, security and stability as free societies.

The United States does not need its neighbours’ resources or their dependence. The United States is a vast country, by far the world’s greatest power, with the largest and most dynamic market, the most productive economy, the dominant currency, vast natural resources and strong economic and security ties across the globe. For this reason, even from a strictly realist perspective, we have no need for imperial possessions or dependent states. This is a characteristic that distinguishes the United States from most of the empires of the past. Furthermore, the Western Hemisphere is our neighbourhood. The negative consequences arising in the region have a direct impact on our country. Thousands of Americans die as a result of the drugs that cross our borders and the crime that accompanies them. Our society has been damaged by mass immigration. Our neighbours have suffered as a result too.

All this demonstrates that the problems in our neighbourhood have a direct impact on the lives of Americans, but it also shows that our aim is not to exploit neighbouring countries. Our interest lies in their success: stability, prosperity and security. Americans will benefit from this because they will have neighbours that no longer export the problems which have plagued the entire hemisphere in recent decades. This concept has been raised in the past, but often within a vision reminiscent of the Peace Corps or the idea that problems could be solved by spending more to tackle their ‘root causes’. Those policies failed largely because they treated our neighbours as dependents. We propose a more realistic and empowering alternative. Our approach does not pit defence against development. Instead, it recognises a fundamental truth: without security, there can be no national development.

This is why our government is not only offering economic opportunities and diplomatic initiatives. We are also reorienting our military and security apparatus in the region to help our partners strengthen the security and stability of their countries and, in the long term, to promote the development of the entire hemisphere through an approach based on shared interests. But this will only work if our partners demonstrate political will, clarity and determination. We call on the countries in the region to make effective use of state institutions and law enforcement to dismantle narco-terrorist networks and secure their borders. Not only to improve public safety, but also to make better use of limited resources and create the conditions for prosperity and development. This may require greater cooperation with the US armed forces, but our aim is for these operations to be progressively led by the partner countries themselves, with their capabilities strengthened through our support. We also call on regional partners to protect their strategic infrastructure. This is essential not only to attract investment and development, but also to ensure lasting peace. Whilst the United States works with allies and partners in other regions of the world to maintain favourable balances of power, we will not ask our neighbours to project power outside the hemisphere. We ask only that they work with us to prevent any hostile actor from seizing and exploiting strategic resources in our region.

Finally, it is essential that our neighbours invest more in their own defence and security. There is no reason why countries threatened by narco-terrorism should allocate so few resources to defence. Some spend as little as 1 per cent of GDP. It defies common sense. Meanwhile, our allies in other parts of the world, including Europe, are significantly increasing their spending: 3.5 per cent of GDP on essential military capabilities and a further 1.5 per cent on security-related expenditure. This is the Trump Corollary to the Monroe Doctrine applied to defence. We believe this represents an effective model for strengthening security and prosperity in the hemisphere. It is a realistic approach, based on aligning the interests of the United States with those of our neighbours and on the willingness to pursue them.

Just over ten years ago, a US Secretary of State proudly declared that the Monroe Doctrine was ‘outdated’. In reality, that approach resulted in a neglect of the real challenges facing our neighbourhood and the defence of our national territory. The result was not a stronger hemisphere with more robust nations, but exactly the opposite. Under President Trump’s leadership and thanks to the Trump Corollary to the Monroe Doctrine, we are following a different and better path, not only for Americans but also for our neighbours. We want strong, reliable and effective partners, not weak and dependent countries. Let’s do this together.