WASHINGTON, Dec 25 — Donald Trump has threatened to seize the Panama Canal, revived calls to buy Greenland and joked about annexing Canada — leaving the world guessing once again whether he is serious or not.

By challenging the sovereignty of some of Washington’s closest allies four weeks before he even returns to the Oval Office, the US-president elect has underscored his credentials as global disruptor-in-chief.

His comments have renewed fears from his first term that Trump will end up being harsher on US friends than he is on adversaries like Russia and China.

But there are also suspicions that billionaire tycoon Trump is looking for leverage as part of the "art of the deal” — and that the former reality television star is grabbing headlines to look strong at home and abroad.

"It’s hard to tell how much of this he really wants, and how much is the latest soundbite that will be heard around the world,” said Frank Sesno, a professor at George Washington University and former White House correspondent.

"He puts other leaders in position of having to figure out what is literal and what is not,” he told AFP.

‘Not for sale’

The idea of buying Greenland is not a new one for Trump. He also raised the prospect of purchasing the vast strategic island, a Danish territory, during his first term in office.

He revived his push over the weekend when naming his ambassador to Copenhagen, saying the "ownership and control of Greenland is an absolute necessity” for US national security.

But he received the same answer this time as he did then, with Greenland’s Prime Minister Mute Egede saying on Monday that the resource-rich island was "not for sale”.

Yet his most headline-grabbing remarks have been on Panama, as he slammed what he called unfair fees for US ships passing through and threatened to demand control of the Panama Canal be returned to Washington.

Trump said on Sunday that if Panama did not agree "then we will demand that the Panama Canal be returned to the United States of America — in full, quickly and without question.”

He also hinted at China’s growing influence around the canal, which was built by the United States in 1914 to link the Atlantic and Pacific oceans. It was returned to Panama under a 1977 deal.

Panama’s President Jose Raul Mulino dismissed Trump’s threats, saying that "every square meter” of the canal would remain in Panamanian hands. Trump responded on TruthSocial: "We’ll see about that!”

Trump also teased neighbouring Canada last week that it would be a "great idea” to become the 51st US state—but against a dark backdrop of threatened tariffs.

‘Message for China’

Sesno said it was hard for other countries to know how to deal with Trump’s comments.

"Well, it’s clearly a joke. Or is it? said Sesno.

"Imagine if you’re the President of Panama, how do you react to something like that? You can’t ignore it and your country will not let you. So the ripple effect of these comments is extraordinary.”

Trump’s harsh treatment of US allies also stands in stark contrast to his repeated praise for the leaders of US foes — including Russia’s Vladimir Putin, who invaded Ukraine in 2022 in a bid for a land-grab.

But there is still likely to be method behind Trump’s rhetoric.

"Maybe the message is for China” when Trump talks about buying Greenland, said Stephanie Pezard, senior political scientist with the Rand Corporation.

Just as Trump expressed concern about Beijing’s influence in Panama, China’s growing presence in the Arctic and its ties with Russia were "something that the US is really worried about,” Pezard told AFP.

But there could also be a signal to Denmark that ‘If you’re too friendly with China, you’ll find us in your way” — even though Denmark and Greenland had been "very good Nato allies.”

And perhaps Trump knows the reality.

Any US plan to "buy” Greenland would be unfeasible "not just in international law but more broadly in the global order that the US has been trying to uphold,” she said. — AFP