BUENOS AIRES (WASHINGTON POST) - United States President Donald Trump's foreign travels have sometimes led to volcanic clashes with fellow leaders, but when Air Force One touched down in Argentina on Thursday (Nov 29) for a Group of 20 (G-20) summit, Mr Trump's hosts had already been straining to please him.

At a conclave typically devoted to issues of trade and the environment, the Argentinians have been trying to minimise topics during the summit that could trigger Mr Trump's Twitter finger - including protectionism, the Paris climate agreement and migration.

In the declaration issued at the end of the meeting - in which leaders sum up their work and set priorities for their underlings - Argentina has been working hard to minimise US embarrassment.

Mr Trump's soft landing may be unsurprising in a nation led by President Mauricio Macri, a former golfing partner of Mr Trump's.

For leaders around the world, the question will be whether Argentina's gentle approach can be more successful than that of Germany, whose G-20 summit last year in Hamburg was tough and confrontational - and included unusual language in the final declaration that made clear that Mr Trump was isolated 19 to one on climate issues.

Just this month, Mr Trump clashed with French President Emmanuel Macron during a World War I-themed trip to Paris, punching out sulphurous tweets about France from Air Force One and holding a rancorous phone call with British Prime Minister Theresa May.

Argentina, by contrast, has backed Mr Trump's tough line on Venezuela.

The Trump administration has supported a US$56.3 billion (S$77 billion) International Monetary Fund rescue plan for Argentina - a position the Argentinians are eager not to jeopardise.

In the negotiations, Argentinian officials say they have worked to address US priorities. The White House has resisted in a final draft the use of terms considered explosive in the American culture wars - including "protectionism" and "Paris accord".

In addition, the Americans have tried to avoid discussing migrants and refugees.

"We're happy to accommodate concerns as we can, and to work toward reasonable wording for consensus," said Mr Pedro Raúl Villagra Delgado, a senior Argentinian diplomat and lead negotiator for the G-20 summit. "This can't be a fight against the United States or any other country."

That is not to say that controversy can be avoided altogether. Mr Trump may cross paths at the summit with Saudi Crown Prince Mohammed bin Salman for the first time since journalist Jamal Khashoggi was killed inside the kingdom's consulate in Istanbul on Oct 2.

Mr Trump has refused to condemn Crown Prince Mohammed, dismissing a CIA assessment that the Crown Prince ordered the killing of Mr Khashoggi, a Washington Post contributing columnist.

The embrace of the Crown Prince puts Mr Trump at odds with several other G-20 nations that have distanced themselves from him, including Canada and Germany.

Also ratcheting up the pressure: A prosecutor in Argentina is considering war crimes charges against Crown Prince Mohammed linked to Mr Khashoggi's death and to the Saudi military intervention in Yemen.

Yet most European leaders are bracing for a different kind of fight, one over issues including the US trade war with China, which Mr Trump and Chinese President Xi Jinping will address in a one-on-one meeting, and Mr Trump's affinity for Russian President Vladimir Putin despite the brewing naval crisis between Russia and Ukraine in the Sea of Azov.

"We must not allow Europe to be smashed between the new poles of power," German Foreign Minister Heiko Maas said this week in speech in Berlin.

"'Europe united' describes the path we have taken, a way forward."

European leaders - many of whom answer to voters who reward confrontation with Mr Trump - acknowledge Argentina's difficult position, and some say they appreciate the effort to calm tensions while preserving tough stances on issues that many rich nations value.

On climate, "it will be language that will convey the same messages" as in Germany last year, said a senior European Union diplomat involved in the negotiations, "but there will be much less specific words".

The diplomat spoke on the condition of anonymity to discuss the sensitive closed-door talks.

"Everyone is fully aware that there is a considerable element of unpredictability in this summit, irrespective of all the preparation work that went into this," the diplomat said.

The Europeans are bracing for difficult conversations about protectionism and the Trump administration's sceptical stance towards the World Trade Organisation.

Even on issues surrounding trade with China, on which US and European leaders are largely aligned, some European officials fear that Mr Trump and Mr Xi could strike a deal that delivers Chinese trade to the US at Europe's expense.

"Dealing with the American administration is of course a challenge for the whole world, because it's slightly unpredictable and it's governed by tweets," Ms Cecilia Malmstrom, the top EU official for trade issues, said at a conference in Brussels this week.

Mr Trump and the Argentinian leader first met in the 1980s, when Mr Trump and Mr Macri's father were mired in a real estate deal.

Rhetorical jabs flew at the time between Mr Trump and the elder Mr Macri, while Mr Mauricio Macri - then an adviser to his father - beat Mr Trump on the golf course.

Decades later, Mr Macri would distance himself from Mr Trump during the 2016 presidential race. After Mr Trump won, he quickly sought to cultivate a sort of South American special relationship with the US leader, drawing on their past and their parallels as businessmen-turned-outsider presidents.

The dynamics of global summits may also be poised for change because of the rise of anti-globallists, further challenging the bloc of liberal democratic leaders in Canada and Europe.

For instance, the October election of Mr Jair Bolsonaro as president of Brazil, Latin America's largest nation, is set to give Mr Trump an influential new ally on the global stage once Mr Bolsonaro takes office next year.

"Trump wants to make America great, and I want to make Brazil great," Mr Bolsonaro said last month.

Given Italy's tilt toward populism, Mr Trump may find that "he is a lot less alone" on the world stage, said an Argentine official who spoke on the condition of anonymity to discuss the dynamics of the summit.

The official said that the leaders representing developing countries at the table this weekend are poised to be more pragmatic about Mr Trump than their European counterparts.

One official described those European leaders as needing to "play to domestic audiences" in home countries where Mr Trump is considered a pariah.

By comparison, developing nations are "more used to unconventional leaders", the official said.