When Donald J. Trump won a return to the White House, many countries thought they knew what to expect and how to prepare for what was coming.
Diplomats in world capitals said they would zero in on what his administration does, rather than what Mr. Trump says. Bigger nations developed plans to soften or counter his threat of punitive tariffs. Smaller countries hoped they could simply hide from four more years of gale-force America First.
But it’s getting harder for the world to keep calm and carry on.
At Tuesday’s news conference at Mar-a-Lago, Mr. Trump declined to rule out the use of force in a potential land grab for Greenland and the Panama Canal. He vowed to rename the Gulf of Mexico the “Gulf of America.” He also said he could use “economic force” to turn Canada into the 51st state as a matter of American national security.
For those eager to parse substance from bluster, it looked like another performance of scattershot bravado: Trump II, the sequel, more unrestrained. Even before taking office, Mr. Trump, with his surprising wish list, has stirred up “here we go again” commentary from across the globe.
Beyond the chatter, however, are serious stakes. As the world prepares for Trump’s return, the parallels between his preoccupations and the distant age of American imperialism in the late 19th century are becoming more relevant.
Mr. Trump has already championed the era for its protectionism, claiming that the United States in the 1890s “was probably the wealthiest it ever was because it was a system of tariffs.” Now, he seems to be adding the focus from the 19th and early 20th centuries on territorial control.
What both epochs share is a fear of shaky geopolitics, and the threat of being locked out of territory with great economic and military importance. As Daniel Immerwahr, an American historian at Northwestern University, put it: “We are seeing a reversion to a more grabby world.”
For Mr. Trump, China looms — ready, in his view, to take territory far from its own borders. He has falsely accused Beijing of controlling the American-built Panama Canal. There is also the specter, more grounded in reality, of China and its ally Russia moving to secure control over Arctic Sea routes and precious minerals.
At the same time, competition is increasing all around, as some nations (India, Saudi Arabia) rise and others (Venezuela, Syria) spiral and struggle, creating openings for outside influence.
In the 1880s and ’90s, there was also a scramble for control and no single dominant nation. As countries became more powerful, they were expected to physically grow, and rivalries were redrawing maps and causing conflicts from Asia to the Caribbean.
The United States mirrored Europe’s colonial designs when it annexed Guam and Puerto Rico in 1898. But in larger countries, like the Philippines, the U.S. eventually chose indirect control by negotiating deals to advance preferential treatment for American businesses and its military interests.
Some believe that Mr. Trump’s fixation on Greenland, the Panama Canal and even Canada is a one-man revival of the debate over expansionist pursuits.
“This is part of a pattern of the U.S. exerting control, or trying to, over areas of the globe perceived to be American interests, without having to summon up the dreaded words ‘empire,’ ‘colonies’ or ‘imperialism,’ while still extracting material benefits,” said Ian Tyrrell, a historian of American empire at the University of New South Wales in Sydney, Australia.
Mr. Trump’s threats of territorial takeover may be simply a transactional starting point or some kind of personal wish. The United States already has a deal with Denmark that allows for base operations in Greenland.
His suggestion of Americanization there and elsewhere amounts to what many foreign diplomats and scholars see as an escalation more than a break with the past. For years, the United States has been trying to curtail Chinese ambitions with a familiar playbook.
The Philippines is again a focus, with new deals for bases the American military can use in any potential war with Beijing. So are the sea routes that matter most for trade both in Asia and around the Arctic as climate change melts the ice and makes navigation easier.
“What the U.S. always wanted was access to markets, lines of communication and capacity for forward projections of material power,” Professor Tyrrell said.
But for some regions in particular, past as prologue inspires dread.
Panama and its neighbors tend to see Mr. Trump’s comments as a blend of both the 1890s and the 1980s, when the Cold War led Washington to meddle in many Latin American countries under the guise of fighting Communism. The Monroe Doctrine, another 19th-century creation that saw the United States treat the Western Hemisphere as its exclusive sphere of influence, has re-emerged into relevance alongside tariffs and territorial deals.
Carlos Puig, a popular columnist in Mexico City, said Latin America was more worried about Mr. Trump’s return than any other part of the world.
“This is Trump, with majorities in both houses, after four years complaining, a guy that only cares about himself and winning at all cost,” Mr. Puig said. “Not easy for a guy like that not to show that he is trying to fulfill his promises, no matter how crazy they are. I am not so sure everything is just bullying and almost comic provocations.”
But how much can Mr. Trump actually achieve or damage?
His news conference in Florida mixed vague threats (“It might be that you’ll have to do something”) with messianic promises (“I’m talking about protecting the free world”).
It was more than enough to awaken other nations, drawing rapt attention and resistance even before he has taken office.
The French foreign minister, Jean-Noël Barrot, on Wednesday warned against threatening the “sovereign borders” of the European Union — referring to Denmark’s territory of Greenland. He added that “we have entered an era that is seeing the return of the law of the strongest.”
What may be harder to see from Mar-a-Lago but is much discussed in foreign capitals: Many countries are simply tired of the America Mr. Trump wants to make great again.
While the United States is still a dominant force, it has less leverage than in the 1980s or the 1890s, not just because of China’s rise, but because of what many nations see as America’s own drift into dysfunction and debt, coupled with the surge in development by other countries.
The international system the United States helped set up after World War II prioritized trade in hopes of deterring conquest — and it worked well enough to build paths to prosperity that made American unilateralism less potent.
As Sarang Shidore, the director of the global south program at the Quincy Institute for Responsible Statecraft in Washington, explained, many developing nations “are savvier, more assertive and capable even as the U.S. has become less predictable and stable.”
In other words, today the world is unsettled. The postwar equilibrium is being shaken by wars in Europe and the Middle East; by the autocratic partnership of China, Russia and North Korea; by a weakened Iran that is seeking nuclear weapons; and by climate change and artificial intelligence.
The end of the 19th century was turbulent, too. The mistake Mr. Trump may be making now, according to historians, is thinking that the world can be calmed and simplified with additional U.S. real estate.
The protectionist, imperialist age Mr. Trump seemingly romanticizes blew up when Germany and Italy sought a greater share of the world. The result was two world wars.
“We saw how that went with 20th-century weaponry,” said Mr. Immerwahr, the author of “How to Hide an Empire: A Short History of the Greater United States.” “It’s potentially far more dangerous in the 21st.”
