“This is the moment of truth,” former Prime Minister Malcolm Turnbull of Australia said in an interview. “They simply have to have the steel to stand up to Trump and tell him what they think, namely, that siding with Putin against Ukraine is a devastating blow to America’s prestige and standing in the world.”
Mr. Turnbull, who had his own clashes with Mr. Trump over refugees early in the president’s first term, said that efforts to charm or cajole him on an issue this fundamental would likely go nowhere. “If the price of getting along with Trump is abandoning your allies, that is too high a price to pay,” Mr. Turnbull said.
A critical problem, said diplomats who dealt with Mr. Trump in his first term, is that he is not the same leader he was then.
“When Trump arrived in 2017, he knew nothing and nobody,” said Gerard Araud, who was France’s ambassador to Washington and accompanied Mr. Macron to multiple meetings with Mr. Trump. “Now he thinks he knows everything, he’s more radical on the substance, and he is surrounded by yes-men.”
That will make it harder for the European leaders to move Mr. Trump off his erroneous claim that the United States, in giving billions of dollars of military support to Ukraine, was essentially the victim of a con job by an unpopular, undemocratic Ukrainian leader. Nor will it be easy, diplomats say, to warn Mr. Trump of the dangers of giving too much away to Mr. Putin in a negotiation.
That doesn’t mean the leaders won’t try.
Mr. Macron, who arrives at the White House on Monday, said during a live broadcast on social media last week, “I’m going to say to him, basically: ‘You can’t be weak against President Putin. It’s not you, it’s not your trademark, it’s not in your interest.’”
Mr. Starmer, who will be in Washington on Thursday, has not publicly shared his strategy for dealing with Mr. Trump. But British diplomats said they expected him to emphasize Britain’s willingness to do more to provide for Europe’s defense by contributing troops to a Ukraine peacekeeping force. Mr. Starmer made the troop commitment last week, but said it would work only if the United States acted as a “backstop.”
“Trump doesn’t do gratitude,” said Kim Darroch, who served as Britain’s ambassador to Washington during much of Mr. Trump’s first term. “But you will at least get some recognition that you are the most forward-leaning of the European countries about buying into his idea of a peace deal.”
British officials said Mr. Starmer would tell Mr. Trump that Britain was considering additional military aid to Ukraine and planned to increase spending on its own defense. Mr. Darroch said Mr. Starmer should pledge to boost Britain’s military spending to 2.5 percent of economic output by a specific date. (Mr. Starmer has promised to reach that threshold but has not set a deadline.)
The prime minister, Mr. Darroch said, should also press Mr. Trump to describe the peace deal he is seeking with Russia and what pressure he plans to put on Mr. Putin to achieve it. While Britain is expected to announce additional sanctions against Russia before Mr. Starmer goes to Washington, Mr. Trump has signaled a willingness to end Russia’s economic and diplomatic isolation.
Mr. Starmer showed some daylight between him and Mr. Trump after the president’s condemnation of Mr. Zelensky, telling the Ukrainian prime minister by phone that he was a “democratically elected leader” within his rights to “suspend elections during wartime as the U.K. did during World War II.”
Having made his point, Mr. Darroch said, Mr. Starmer should avoid getting drawn into a debate with Mr. Trump over Mr. Zelensky. Instead, he said, the prime minister should play to Mr. Trump’s vision of himself as peacemaker.
Mr. Araud agreed, saying: “It would be a mistake for the Europeans to argue with Trump about who started the war, or whether Zelensky is a dictator. That is a non-starter for a Trumpian approach.”
Mr. Araud said he expected Mr. Macron to press Mr. Trump for security assurances in return for Europe’s assembling a deterrent force. France and Britain are trying to persuade Sweden, Denmark, the Netherlands and the Baltic countries to join such a force.
Other French officials said they worried that Mr. Trump would insist on putting a cease-fire in place in Ukraine within weeks, with a goal of celebrating it with Mr. Putin in Red Square in Moscow on Victory Day, which commemorates the Soviet victory over Nazi Germany, on May 9. He would be the first president to visit Russia in more than a decade — striking evidence of Mr. Putin’s diplomatic rehabilitation.
With little time to prevent that, French officials said they were scrambling to limit the damage. Among their deepest fears is that Mr. Trump will try to force an election in Ukraine, which would open the door to Russia-backed candidates, online smear campaigns and other forms of election interference.
Some experts argue that the leaders should appeal to Mr. Trump’s other priorities, notably America’s competition with China. Conceding too much to Mr. Putin, they said, could embolden China in its designs against Taiwan. It would also give China an incentive to draw closer to Russia in a coalition against the United States.
“If you make peace or impose peace in Europe and on Ukraine, on terms favorable to Russia, that actually makes it harder for you to deal with China,” said Nigel Gould-Davies, a former British ambassador to Belarus who is a senior fellow at the International Institute for Strategy, a research organization in London.
But Mr. Gould-Davies and other analysts said that drawing Mr. Trump into a discussion of grand strategy had its limits. “For Trump, even more than most leaders, the personal is the political,” he said.
On Friday, Mr. Trump described Mr. Macron as a friend, but complained that neither he nor Mr. Starmer had “done anything” to end the war.
Mr. Starmer and Mr. Macron have both worked to cultivate Mr. Trump. Mr. Starmer did not get to know him until a dinner at Trump Tower in New York last September, but the two seemed to get along. “I like him a lot,” Mr. Trump said recently. “He’s liberal, which is a bit different from me, but I think he’s a very good person.”
Mr. Macron’s relationship with Mr. Trump goes further back and has weathered more bumps. After a honeymoon period marked by Mr. Trump’s attendance at the French military parade, the two leaders clashed over Mr. Trump’s decision to pull out of the Paris climate accord and the Iran nuclear deal.
Mr. Macron continues to reach out. In December, he invited Mr. Trump to attend the reopening of the Cathedral of Notre-Dame in Paris. He also scrambled to get on the president’s calendar in Washington before Mr. Starmer, whose Washington trip has been in the works for a few weeks.
None of that guarantees that his diplomatic efforts will work this time. During a state visit to Washington in 2018, Mr. Araud recalled, Mr. Macron mistakenly believed he had talked Mr. Trump into not withdrawing from the Iran deal.
“There is this element of unpredictability and unreliability,” Mr. Araud said. “Whatever he says on Day 1 doesn’t mean anything on Day 2.”
Catherine Porter contributed reporting from Paris.
