‘Here We Go Again’: Trump’s Territorial Ambitions Rattle a Weary World

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 19th and early 20th century’s focus on territorial control.