After its inception in 1823, the Monroe Doctrine was largely ignored. But after a while, different administrations saw the value in maintaining control over the western hemisphere. And notably, it is having a renaissance in the Trump presidency.
So what IS the Monroe Doctrine? How has it been interpreted in various presidencies? And, most importantly, is it legal under international law? Civics 101 regular Dan Cassino takes us from Monroe to Maduro.
Click here to listen to our episode on the history of Venezuela leading up to America's invasion in 2026.
Transcript
Speaker1: The Monroe Doctrine is a big deal, but we've superseded it by a lot.
Speaker2: Secretary of Defense Pete Hegseth issued an order to, quote, kill everybody on the vessel.
Speaker1: By a real.
Speaker3: Life Panama Canal is ours. Trump should mind his own business. And all countries have the ability to use the Canal Monroe Doctrine.
Speaker1: We sort of forgot about it. We're very important, but we forgot about it. We don't forget about it anymore.
Nick Capodice: You're listening to Civics 101. I'm Nick Capodice, [00:00:30] I'm.
Hannah McCarthy: Hannah McCarthy.
Nick Capodice: And today we are talking about a 200 year old written statement by a president that didn't really mean much until it did. The Monroe Doctrine, what it was, what it became, how it was used over the centuries, and why everybody is talking about it right now. Stick around.
Hannah McCarthy: All right, Nick, we're talking about the Monroe Doctrine. Let's start with what it is. James Monroe, our fifth president. [00:01:00] Was this something that he wrote? Was it an executive order?
Nick Capodice: All right. Well, I got to set the scene first, Hannah.
Hannah McCarthy: All right.
Nick Capodice: It's the 1820s. We got the War of 1812 in a rear view. We've got a national purpose. I'm okay. You're okay. It is the moment in history known as the ERA of Good Feelings.
Hannah McCarthy: In other words, the period when the Federalist Party collapses, the Democratic-Republicans run the show, and seemingly nobody is disagreeing about [00:01:30] anything.
Nick Capodice: Anything at all. And ask your question, Hannah. What is it? This is something written sort of by James Monroe, but it is not an executive order.
Dan Cassino: All right. So 1823, this is the seventh state of the Union address from President James Monroe.
Hannah McCarthy: Dan casino. It has been too long.
Nick Capodice: Every moment a treasure with Dan Casino.
Hannah McCarthy: Is Dan still professor of government and politics at Fairleigh Dickinson University?
Nick Capodice: You know it.
Dan Cassino: Yep. You know, it was fun. I, one of my colleagues, a history professor [00:02:00] got a text from his son and said, wait, do you know Dan Cassino? We heard his stuff.
Nick Capodice: James Monroe gives his state of the Union address in 1823.
Dan Cassino: Remember, state Union is not him giving a talk to Congress. It's. He just writes a letter. They didn't give talks to Congress until the 20th century.
Nick Capodice: Here's what I'm going to note, though. Hannah. It was Monroe's state of the Union. But these words were not written by him. They were written by Monroe's then secretary of State, John Quincy Adams.
Dan Cassino: So embedded [00:02:30] in this very long state of the Union address, he has this little statement where he says that foreign countries, European countries should not get involved in South America or in the Western Hemisphere.
Hannah McCarthy: One more time to make sure I've got it. Europe should not meddle with countries in the Western Hemisphere.
Nick Capodice: Right.
Hannah McCarthy: And what's the follow up to that “Should”
Nick Capodice: What do you mean?
Hannah McCarthy: Well, if Monroe says, don't do this, it seems like there should be some sort of. And if you do, like a consequence dot dot dot.
Nick Capodice: Right, right. It's the sort of thing that should be followed up with or else, you know.
Dan Cassino: But it's not. It's just a period [00:03:30] because America doesn't really have much of an army or navy at this point. So we are just making as a statement of policy, there should be no more colonies in South America.
Hannah McCarthy: All right. But why? What is the problem with European government getting involved in South America?
Nick Capodice: Well, we've got to think in the geopolitical context of the 1820s here.
Dan Cassino: Remember, so America has this revolution. You have the French Revolution. Looks like republics are taking over Europe. But by the time you get to 18, 15, 18, 16, there's been a retrenchment of monarchies.
Hannah McCarthy: A retrenchment [00:04:00] of monarchies.
Nick Capodice: Like the Empire dress and Beethoven piano sonatas. Monarchies are so back.
Dan Cassino: This is right after the defeat of Napoleon, right? And you get Poland. Russia and Austria form this alliance. Pro monarchic alliance. Putting a monarchy back in France. So we are having a resettlement of monarchies. You know, the republican fervor has finally passed and monarchies feel like they're safe going forward. And monarchies are taking back over. [00:04:30] There's a fear that those monarchies are going to try and reconquer the South American countries that had already had revolutions against the monarchy and established republics. The idea we're putting forward here is that these new republics that have been formed in South America should not be reconquered. You shouldn't try and make them back into monarchies because the old world. Okay. You guys have monarchies. We accept that. Fine. Whatever. But the new world should be republics.
Nick Capodice: And again, there is no [00:05:00] or else in there. And what we now call the Monroe Doctrine sort of floats into the mist.
Dan Cassino: So no one pays any attention. Nobody cares because America doesn't have much money, doesn't have much of a Navy. We just got our butts kicked in. The War of 1812 like this is not really much of a statement. We know, like Simon Bolivar hears about this and goes, ah, that's nice, I guess. I mean, like, no one is really taking this seriously. In fact, the only one who takes this seriously is the British, because this is really good for [00:05:30] the British.
Hannah McCarthy: Why is this good for the British?
Nick Capodice: It's good because of one word mercantilism.
Speaker7: The best things in life are free. But you can give them to the birds and bees I want money.
Dan Cassino: We don't talk about mercantilism enough. But mercantilism. All right. Mercantilism is the economic theory that in theory, Adam Smith put an end to. But in practice he did not. That the way you get the strongest and best country The strongest and best economy is by accumulating as much gold as you possibly can. If [00:06:00] you get the most gold, you win. What do you win? We don't ask questions like that, but you win if you get the most gold. So your trade policy under mercantilism is to get as much gold as possible. How do you get gold? You sell stuff to other countries because they're going to pay you in gold. So whenever I sell something in another country, some of the gold, they're gold gets transferred over me and I get their gold at the same time while I'm selling stuff. I am not buying anything, because when I buy something, gold comes out of my coffers and goes to my potential enemies. So my job is to sell as much [00:06:30] as possible and not buy anything, which kind of falls apart when you start to make this economic theory that's applying to an entire continent, because everyone is trying to buy trying to sell stuff and nobody wants to buy anything. So indirectly, this is, of course, what actually leads to colonialism. The idea that I need to find other stuff that they don't have in their country that I can sell to them, so they have to buy it from me. Ideally an addictive substance like caffeine or tobacco or something, opium, whatever. And if that doesn't work, then my colonies work as a captive audience. They have to buy [00:07:00] my stuff. Right. And I get gold from them. So this is a huge deal geopolitically in the 18th and 19th centuries.
Hannah McCarthy: Now, what did Dan mean when he said Adam Smith supposedly put an end to mercantilism, but actually didn't?
Nick Capodice: Yeah. So Adam Smith was a renowned economic philosopher who published a treatise in 1776 explaining why some nations are rich and some nations are poor, and that mercantilism is not the way to go to ensure [00:07:30] success. The short name of this treatise is The Wealth of Nations.
Dan Cassino: In theory, you know the Wealth of nations put an end to this. You know, it was a very definitive proof that this didn't actually work. And the true Wealth of nations is in the bounty and the production of your people. But nobody really bought that for at least another 40 or 50 years. So the British love this idea because all these newly freed Republicans, South America? Well, they're not part of the mercantilist system that the Spanish or whoever [00:08:00] previously owned them are part of. So previously, if Brazil is owned by Portugal, Brazil ain't trading with anybody, right? The British can't trade with Brazil, right. Because they're part of the mercantilist system with Portugal. You know, all the you know, Mexico is with Spain is with Spain. You can't trade with them because they're tied up with Spain.
Hannah McCarthy: So big, powerful European countries like Portugal and Spain, if they take over a country in South America, that makes it a lot harder for Britain to trade with that country, to get stuff [00:08:30] from South America that you can't get anywhere else like bananas.
Nick Capodice: Oh, man. Hannah, we are gonna get to bananas.
Hannah McCarthy: Really?
Nick Capodice: Oh, yeah. But yes, it is easier for Britain to trade with a small, independent republic that needs the money and doesn't have a big whanging army behind it. And remember, at this time Britain has the biggest navy in the world.
Dan Cassino: So the British become the biggest defender of the Monroe Doctrine, basically saying to other countries in Europe, no, no, [00:09:00] no, you can't go back in and reconquer this place and reconquer your your former colony, South America, because the Monroe Doctrine. Right. That's that's the whole thing over here. So the British become the defender of this throughout the 19th century, and the Americans do basically nothing with it.
Hannah McCarthy: Okay. So when does America finally start to care about the Monroe Doctrine?
Nick Capodice: First, a few little dribs and drabs. President James K Polk hints at it a little bit to justify manifest [00:09:30] Destiny and the Mexican-American War, but the rise of the Monroe Doctrine into something that actually affects American policy going forward is in the 1850s. And before we get to that, we've got to take a quick break. We are back. You're listening to civics 101, and we are talking about the Monroe Doctrine. Just a reminder to our listeners. We have hundreds and hundreds of episodes [00:10:00] at our website, civics101podcast.org. Just check it out if you need a refresher on just about anything.
Hannah McCarthy: Okay, Nick, you were going to tell me about the point at which the Monroe Doctrine actually started to matter. When does that happen?
Nick Capodice: All right. But first, Hannah, a quick word on the name, the Monroe Doctrine. Here again, is the inimitable Dan Cassino.
Dan Cassino: It doesn't even get called the Monroe Doctrine until sometime in the 1850s. No one thinks about it. No one calls it a doctrine. No one. This is just something Monroe [00:10:30] said until the 1850s, where it becomes starts to get more important. Now, why is it get more important? It gets more important because America gets a bigger army and navy, so we can actually start to do stuff. And so the first time we actually see the Monroe Doctrine actually coming into effect in any sort of recognizable form is the Spanish-American War, where we're going into Cuba and saying, no, no, no, we have this long standing doctrine that we've never enforced before For saying that you, Spain, cannot have Cuba. No one can do this now. During the period between the 1820s and the 1890s, [00:11:00] lots of European powers came in and muddled around South America. I mean, the French conquered Mexico and installed an emperor in Mexico.
Hannah McCarthy: So Spain and France were actually acting against the Monroe Doctrine.
Nick Capodice: They were we said, don't do this. And they just didn't listen.
Hannah McCarthy: Okay. And why didn't we do anything about it?
Dan Cassino: Uh, we didn't do anything about it because it was 1862, and we were a little busy doing other things at the time, but there was not a whole heck of a lot America could do about it because we didn't have an army or Navy, right? We had no way of enforcing [00:11:30] these rules. We'd, in theory, put into place. And again, no one even thought of them really as being rules. Okay, so Spanish-American War, we're going in conquering all of these territories to free them from the yoke of European oppression. And it's Teddy Roosevelt who's, of course, very deeply involved in the Spanish-American War, who puts his corollary, we call it the Roosevelt Corollary to the Monroe Doctrine this moment.
Nick Capodice: Hanna, this is a huge yes. And to the Monroe Doctrine. This is how Teddy Roosevelt justified [00:12:00] the war where the US took over Puerto Rico, Guam, the Philippines. And it also began our protectorate relationship with Cuba.
Hannah McCarthy: And what is the corollary? Exactly.
Dan Cassino: The Roosevelt Corollary is, again, all about economics. His argument is that we as America, we are responsible for the economic and social well-being of the Americas writ large. And what that means in practice [00:12:30] is that if a country in South America is going to default, right, if their trade policy is out of whack and they're going to default, we Americans are going to step in and get things back on track so the Europeans don't have to. The way we're going to keep Europe out of South America is by going into South America ourselves and regulating the economies, regulating the government of South America to make sure that the European powers don't actually have to do that.
Hannah McCarthy: So now it's not just, hey, Europe, stay out of South America. It's we here in the US are responsible for maintaining [00:13:00] the economic stability of South America.
Dan Cassino: Yeah, we're taking over from the British. Now. We want to do all the trade with everyone in South America. Right. And look, there is a real fear that if, uh, you know, Venezuela defaults on its loans, that the British going to come in and invade, because that's what you did at that time. And so we're saying, look, we're going to make sure Venezuela, whoever doesn't default on its loans, their economy doesn't get out of track. They don't nationalize stuff. We're going to make sure that that never happens in order to not give the Europeans an excuse to come in.
Nick Capodice: And here [00:13:30] Hannah, is where we get to the bananas.
Dan Cassino: And you get America becoming very, very active in South America and Central America. And this is because of the expansion of American companies into Central America and South America, mostly fruit companies. You're getting fruit, you're getting sugar and all these things. And so America expands its military presence in South America and Central America to protect American business interests. This actually leads America to a series of wars between about 1920 and 1934, colloquially known as the Banana Wars, and [00:14:00] the Banana Wars are the the truest expression of the Monroe Doctrine, where we just send in the Marines to protect American business interests.
Nick Capodice: So we had just finished the Panama Canal. Trade from South America was now significantly easier, and the US owned a lot of fruit companies down there, namely Dole and Chiquita, then named the Standard Fruit Company and the United Fruit Company.
Dan Cassino: So if you're the United Fruit Company, we're going to invade. We're going to attack. If you're under attack again, [00:14:30] we have to make sure that their economies are being run properly, because if their economies are not being run properly, that would, in theory, give an excuse to Europeans to come in and do something about it. But we're not really worried about that. But we're saying our business interests are supposed to be dominant here in South America and Central America. So therefore we are obliged to do whatever the heck we need to do in order to protect those business interests. Um, the Banana Wars are very, very bloody. I mean, we are talking, you know, thousands of American Marines [00:15:00] are killed in these banana wars. Uh, but that's nothing compared to the tens or hundreds of thousands of Central and South American people who are killed in these banana wars, essentially to protect American business interests and to keep the flow of tropical fruit into America and tropical fruit, sugar in America going strong.
Hannah McCarthy: So this is US owned companies using the American military as protection.
Nick Capodice: Exactly. Before this, a company would and did hire private security firms like the Pinkertons to be the muscle. [00:15:30]
Speaker8: I don't like the Pinkertons.
Nick Capodice: But now you've got the US armed forces.
Dan Cassino: Look, these are colonial economies. These are colonial plantation economies. In a plantation economy, the only people who have money are the people who own land. Right? And everyone else has no money, has no nothing. Because all the wealth comes from land, from owning where the crops are growing. And so it turns out, if you have a bunch of Americans who come in and own all of the land in the country, the locals get a little squirrely about this. They're unhappy, and sometimes you get revolts. And what are these? What are these poor American business owners supposed to do? If you [00:16:00] want to keep the flow of pineapples and bananas going to New York? Well, you call in the Marines.
Hannah McCarthy: The banana Wars ended, didn't they?
Nick Capodice: They did.
Hannah McCarthy: Why?
Dan Cassino: For a couple reasons. The big one being the Great Depression and the buildup to World War two. Like we need those Marines for other things. Weirdly, public support for supporting businesses and supporting business oligarchs [00:16:30] drops during the Great Depression. Like, I don't know, public opinion is not there. Um, and President Franklin Roosevelt's not really as big on this as, like, Calvin Coolidge would have been because, you know, Calvin Coolidge, he'll call it the Pinkertons on anybody on a moment's notice. So Franklin Delano Roosevelt's not as big on this. Knows we're building up to war in Europe. So, you know, these things wind up, you know they die down. So Franklin Roosevelt, you know, basically pulled the troops out and lets the business owners, you know, fend for themselves, which, again, is not really too much of a problem. Private security forces, things like that.
Speaker8: I [00:17:00] don't like the Pinkertons.
Dan Cassino: So we essentially don't need to send the military all over the place.
Nick Capodice: But after World War Two is over, when all the soldiers and the marines and the ships and the tanks were no longer needed in Europe, when the US is embroiled in a Cold War, the Monroe Doctrine has another renaissance. And this time it's not just protecting economies of other nations. It's about ideas.
Speaker9: Like an iceberg. Much communist [00:17:30] activity is out of sight in the underground. But here and there, signs appear.
Dan Cassino: Yeah, we are in the Cold War era, and during the Cold War era, there is a long standing tradition of America intervening in South American countries and South American governments, and this can be seen as an offshoot of the Roosevelt Corollary, the idea that our job is to maintain stability. And just by the 1950s through 1970s, we have redefined stability to mean not socialist. So because socialism is basically [00:18:00] communism, and you know how the domino theory works, if one country goes communist, then they all go communist. During the Cold War, we have to protect South America from socialist governments. And so we oftentimes don't do this with the military anymore. We're going to do this with the CIA because or with other secret means, because we don't want to get the blame for it, because people will be very upset at us if they know what we were doing.
Hannah McCarthy: Okay. As we're starting to get nearer to the modern era. Nick, I have to ask something I should [00:18:30] have asked at the beginning. Is this allowed? Can we invade a foreign country because we don't like their ideals? I know we have done it many a time under various justifications and names, but is this in line with international law?
Dan Cassino: No. Absolutely not. International law going back to the Treaty of Westphalia is supposed to say that you can't intervene in other countries without a casus belli. Um, but we look, we're at this point we're a very powerful country. And that [00:19:00] means international law doesn't really apply to us.
Nick Capodice: And I'm going to come back to that point because it's a big one. But the US continued to involve itself with affairs in the Americas, most notably in Panama in the 1980s.
Dan Cassino: And the arrest of Manuel Noriega in 1989 on drug trafficking charges, which looks very much like recent events. But in that case, we send the Marines. We invade and occupy Panama for a month while we're looking for the guy. So there's lots of times where we're still saying the Marines, but not nearly as much as we were earlier, because we don't really need to [00:19:30] as much as we did before, because we're making sure the governments that in South America are relatively friendly to us.
Speaker10: Multiple explosions and low flying aircraft were seen in Caracas in the early hours of Saturday morning. Maduro's government immediately accused the US of an imperialist attack on civilian and military installations.
Hannah McCarthy: We did an episode a few weeks back on what happened in Venezuela on January 3rd, 2026. We've got a link to that in the show notes. If anyone wants the big picture on the history leading up to the capture of Nicolas Maduro, but I will [00:20:00] just share right here. Donald Trump cited the Monroe Doctrine specifically in justifying the invasion of Venezuela.
Speaker1: The Monroe Doctrine is a big deal, but we've superseded it by a lot.
Dan Cassino: President Trump was very clear about the Monroe Doctrine, as President Trump often does. He talked about as if no one had ever heard of it before. He said, this is no doctrine. It's very big right now. Um, people forgot about it. They're not gonna forget about it again. So, yeah, he absolutely cites it as part of the justification for this.
Speaker1: Under our new national security strategy, American [00:20:30] dominance in the Western Hemisphere will never be questioned again.
Nick Capodice: The doctrine was explicitly called out in Trump's National security Strategy, released in 2025, which announced a quote unquote Trump Corollary, which was to quote, reassert and enforce the Monroe Doctrine to restore American preeminence in the Western Hemisphere. End quote. The Trump Corollary has been referred to by the Trump administration as the Donroe doctrine. [00:21:00]
Speaker1: They now call it the Donroe document. I don't know, it's, uh, Monroe Doctrine.
Nick Capodice: And it was not just used to justify the Venezuela invasion, but the renaming of the Gulf of Mexico, the proposed acquisition of the Panama Canal, the blowing up of boats in the Caribbean, and also which we're going to have to get to in a future episode as things unfold. I don't even know how to refer to it. The explicit intended taking of Greenland.
Speaker1: And I'm [00:21:30] a man. And by the way, I'm a fan of Denmark, too, I have to tell you. And and, you know, they've been very nice to me. Uh, I'm a big fan, but, you know, the fact that they had a boat land there 500 years ago doesn't mean that they own the land. Uh, we had lots of boats go there also.
Hannah McCarthy: Can we get back to what Dan said about international law? That the Monroe Doctrine is not applicable under international law. Because under international law, we do not invade unless [00:22:00] someone threatens or provokes us, or unless that country asks us to. How do we square that? What happens when we ignore international law?
Dan Cassino: This is reflects a very 18th century understanding, a pre-modern understanding of international law. You know, this is, you know, the Greeks during the Peloponnesian War, those who can do and those who can't suffer. I mean, we have power so we can do whatever the heck we want. And this is not the way the modern, rule oriented [00:22:30] post 1945, uh, world system is supposed to work. You have to remember. So in 1945. Right? America, we are the dominant power on earth. Everyone else has been blown to smithereens, partially by us. And what we do, We've got this hegemonic moment where we're the only ones with the nuclear bombs, the atom bombs, like we have everything. And we could use that to become the global hegemon. But instead, what we do is we say, all right, we are going to establish all these international organizations like the UN and all these other things that are going to regulate [00:23:00] trade and regulate international relations. And then we're going to give ourselves a privileged position within those organizations. But everyone gets a voice, and that way everyone will buy in to America being the leader of the world.
Dan Cassino: And we'll be able to maintain this kind of global dominance for much, much longer if we just try and do basically everything we've got. The atom bomb and you don't. Well, in ten years everyone's gonna have an atom bomb, so it's not going to work. But we can build these organizations. Yeah. The General Agreement on Tariffs and Trade, the World Trade Organization, the you [00:23:30] know, the UN, we can build these organizations and that'll extend that hegemony for much, much longer because we'll get everyone to buy into it. And so when we go ahead and abandon, really the rules we set up to deal with exactly this kind of thing. We abandoned those rules. We are giving permission to other people to abandon those rules as well. And that's really troubling, because one thing that's made the world safer in the last 80 years has been this rules oriented, you know, norms based, international organization system. [00:24:00] And when we get rid of that, that causes problems and doesn't cause problems just for other people, causes problems for us.
Nick Capodice: That is the Monroe Doctrine today on Civics 101. This episode is made by me Nick Capodice with you, Hannah McCarthy. Marina Henke is our producer and Rebecca LaVoy, our executive producer. Music. In this episode from The Usual Suspects, Epidemic Sound, blue Dot sessions, [00:24:30] and the tremendous Chris Zabriskie. Civics 101 is a production of NPR, New Hampshire Public Radio.