Chances are you haven't heard the term "manifest destiny" since high school history class. That is until President Trump's inaugural address last month, when he used it to call for America to "plant the Stars and Stripes on the planet Mars."
The 19th century term describes a belief in American exceptionalism and a divine right to expand into lands in North America where indigenous people and Mexicans lived. "It's fascinating to see this term come back, because the whole concept of expanding the country, of course, is at the core of the American experience," Michael O'Hanlon, a senior fellow at the Brookings Institution, says.
When Trump discusses the U.S. acquiring Greenland, making Canada the "51st state," threatens to "take back" the Panama Canal and most recently suggested the U.S. would take over Gaza, he wipes the dust off other notions of American imperialism that haven't been an overt part of U.S. aims since the days of Teddy Roosevelt.
Trump, O'Hanlon says, "has a long historical tradition to build upon."
What is the origin of the term "manifest destiny"?
James K. Polk won the presidency in 1845 on an explicitly expansionist platform: acquire California and other land in the Southwest, annex the then-independent Republic of Texas and settle a dispute with Britain for control of the Oregon Territory. (Another Polk promise, by the way: reducing import tariffs).
The term manifest destiny was coined by journalist John O'Sullivan that year in an essay praising the annexation of Texas and looking ahead to California — then part of Mexico — as being the next.
More generally, the term was a form of American exceptionalism that came to mean the inevitable east-to-west occupation of the North American continent, often expressed in messianic terms.
Although the term was created in the 19th century, it hearkens back to the first European settlers who believed their quest was divinely inspired, according to the Smithsonian American Art Museum.
"Manifest Destiny was meant as this notion that America was destined to control all of this territory... we have to have all of this land because we were exceptional," said Susan D. Page, the first U.S. ambassador to South Sudan, who's now a professor at the University of Michigan Law School.
Does the term describe Trump's brand of diplomacy?
In part. "There are some surface-level parallels," says Will Freeman, fellow for Latin America Studies at the Council on Foreign Relations. "It seems Trump and those around him are fairly serious about making this a time of U.S. territorial expansion."
But when Trump talks about Canada, Greenland and Panama, he also taps into manifest destiny's source code — the Monroe Doctrine, first espoused by President James Monroe in 1823 as a warning to European powers against interfering in the affairs of the Western Hemisphere. As Stewart Patrick, a senior fellow at the Carnegie Endowment for International Peace notes, Polk invoked the Monroe Doctrine as a justification first for annexing Texas — to prevent it from becoming "an ally or dependency of some foreign nation more powerful than [the United States]," in Polk's words — and later for war with Mexico (1846-1848). In 1867, President Andrew Johnson similarly cited it as a rationale for purchasing Alaska.
"The Monroe Doctrine historically has been the United States' way of relating to its own sphere ... although it's changed meaning over time," Freeman says.
By the end of the 19th century, the Monroe Doctrine took on a more robust implication, Patrick notes. It was "understood to imply that the entire Western Hemisphere was an American preserve," he writes.
Another historical parallel can be drawn with Trump's aggressive use of tariffs and threats of them and the arrival in 1853 of a flotilla of U.S. warships in Tokyo Bay. The ships were meant to bully Japan into opening its ports to U.S. trade. The tactic came to be known as "gunboat diplomacy" and it would be reshaped by President Theodore Roosevelt into his "big stick" maxim of persuasion coupled with the threat of force to achieve goals on the international stage.
"Trump seems to be reinventing 'big stick diplomacy' in the Americas for the 21st century, only without the 'speak softly' part," says Freeman.
But in doing so, he says, Trump "will face constraints."
"The United States does not have the unrivalled power in the hemisphere it was beginning to gain in the days of Teddy Roosevelt," Freeman says. "Now there is China to compete with, and in most of South America, China's economic weight is decisive.
"His 'big stick' will be most effective, ironically, in the countries he needs it least — those north of Panama which are already for the most part tightly integrated into the United States' orbit," he says.
It's also worth noting that Trump has also long espoused isolationist rhetoric, calling for the U.S. to remove itself from world conflicts and accusing American military allies of not paying their fair share.
What would it mean if Trump followed through?
If Trump follows through on his expansionist rhetoric, the U.S. "would essentially become an international pariah," O'Hanlon, of Brookings, says.
"If we use military force to seize the Panama Canal or Greenland... it would [put] us in the same category... as Vladimir Putin," he says.
But having made the comments, backing off of them could also be difficult, Freeman says. When Trump says he's going to slap 25% tariffs on Colombia, but then settles for a resumption of deportation flights, for example, "it's kind of the boy who cried wolf," Freeman says. "So I think that maybe what he's able to get out of each of these, what he's able to leverage out of each of these threats is going to probably decrease as leaders realize, 'well, he doesn't really mean what he says,' but, you know, he's also quite unpredictable."
Being unpredictable can be its own long-term problem, according to Page, the former ambassador. As an example, she points to the North American Free Trade Agreement (NAFTA), and its successor, the United States-Mexico-Canada Agreement (USMCA) negotiated and signed during Trump's first term.
"How can you threaten your two other partners with tariffs when you have a trade agreement with them?" she wonders. If Trump can do it, "that means that the next administration can then go against whatever those previous policies and agreements were."
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