WASHINGTON — On Sept. 16, 1991, Angela Merkel, then a young protégé of Chancellor Helmut Kohl of Germany, watched in the Oval Office as her boss and President George Bush wrestled with the sudden collapse of the Soviet Union. Without an influx of emergency aid, Germans feared that refugees could pour across the border, threatening the stability of their newly reunified country.
Ms. Merkel shared that memory with President Trump at a summit meeting in Buenos Aires the morning after Mr. Bush’s death. Later, she told reporters, “Helmut Kohl could rely on this friend of the Germans in the White House.” If not for Mr. Bush’s sure-footed handling of those historic events, Ms. Merkel added, she “would hardly be standing here.”
With Mr. Bush’s death, a generation of Cold War leaders has passed from the stage. Of the major figures of that era, only Mikhail S. Gorbachev, the Soviet Union’s last leader, is still alive. But at 87, he is too ill to attend Mr. Bush’s funeral. Mr. Kohl died last year; even his protégé Ms. Merkel, who went on to become Germany’s first female chancellor, is now in the sunset of her political career.
Ms. Merkel’s reminiscences about Mr. Bush were all the more poignant, given that she was about to sit down with Mr. Trump, who grew up during the Cold War but has gleefully tried to dismantle the European and global institutions that Mr. Bush and his Cold War-vintage colleagues built.
“What Merkel is viscerally remembering was the American-European partnership at its height, in a period of emergency and world crisis,” said Philip D. Zelikow, who advised Mr. Bush on German reunification and the breakup of the Soviet Union. “Now here were are, as the system these leaders created is drifting into great jeopardy.”
“What exactly is the partnership that is managing this now?” he asked.
It is easy to forget, as the tributes to Mr. Bush pour in, that these Cold War partnerships were not without their bumps. While Mr. Bush and Mr. Kohl agreed on the need for food and medicine for the Soviets, they differed over how quickly to provide economic assistance. Mr. Bush wanted the Soviets to undertake sweeping market-oriented changes first.
Some analysts argue that it is pointless to pine for the restoration of the American-led international order that Mr. Bush helped create. That system was beginning to fray well before Mr. Trump took office, for all sorts of reasons unrelated to him, and it is likely to keep unraveling, regardless of who follows him into the White House.
“This is essentially the old adage about generals always fighting the last war,” said John C. Kornblum, a former American ambassador to Germany who now works as a consultant and commentator in Berlin. “There is nothing to save. We are already deeply into the new order.”
Still, Mr. Kornblum and others said, there were lessons to be learned from Mr. Bush’s approach to foreign policy, which can be applied to the upheavals of today. He was a master at building coalitions, a skilled diplomat who understood how to corral balky allies, like Britain and France, and deal adroitly with failing adversaries, like the Soviet Union.
By declaring his faith in a united Germany, even before the fall of the Berlin Wall, Mr. Bush helped secure a united Europe. He also frustrated last-ditch Soviet efforts to dissolve the Atlantic alliance. Mr. Gorbachev paid his respects.
“We had a chance to work together during the years of tremendous changes. It was a dramatic time that demanded great responsibility from everyone,” Mr. Gorbachev told the Interfax news agency. “The result was an end to the Cold War and the nuclear arms race.”
In addition to winding down the Cold War, historians credit Mr. Bush with helping facilitate the reunification of Germany and Europe, as well as the peaceful dissolution of the Soviet Union. And he was an apostle for free trade, negotiating the North American Free Trade Agreement and laying the groundwork for the World Trade Organization.
“We had a leader in Bush who had a superb sense of timing, who knew when to coddle and when to cajole,” said Josef Joffe, a member of the editorial council of the German newspaper Die Zeit.
“Trump doesn’t believe in give and take, and preserving the dignity of the adversary,” Mr. Joffe said. “He is just the real estate guy who says you either take it or leave it.”
The contrast with Mr. Bush was on stark display at the Group of 20 meeting in Buenos Aires. Mr. Trump declared that he and Ms. Merkel would talk about trade, saying that Germany knew how unacceptable Americans found its trade surplus. As Ms. Merkel has pointed out to him in previous meetings, Germany, as a member of the European Union, cannot negotiate independently on trade with the United States.
Mr. Trump did not mention the issue that most concerned Germany at this meeting: the clash between Russian and Ukrainian naval vessels, which the Germans view as a drastic escalation of President Vladimir V. Putin’s predatory behavior toward his neighbor.
Nor did he mention Ms. Merkel’s struggle to keep the European Union intact, amid a wave of nationalist fervor across the Continent. To the extent that Mr. Trump mentions the bloc at all, he tends to disparage it.
Mr. Trump’s aides played up their effort to discredit another of Mr. Bush’s legacies, the World Trade Organization. The communiqué released by the Group of 20 after the meeting said, “the system is currently falling short of its objectives and there is room for improvement” — language inserted at the request of the United States.
“Bush and Kohl were talking about creating the W.T.O,” Mr. Zelikow said. “That’s the very conversation that Merkel was remembering, from her opening moments on the world stage.”
As Mr. Trump has gotten to know Ms. Merkel over the last two years, their relationship has become laden with symbolism: the great disruptor facing off against the last defender of the liberal world order. But it is not clear Mr. Trump fully grasped the contradictions between Ms. Merkel’s encounter with Mr. Bush, and his relationship with her.
“He was a wonderful man,” Mr. Trump said, as they faced the cameras last weekend. “And you may want to just explain your little meeting with him. I found it very interesting.”
“Yes,” Ms. Merkel replied in English. “I was with Chancellor Kohl in the White House, visiting George Bush. And he’s the father, or one of the fathers, of the German unification, and we will never forget that.”
“I found that very interesting,” Mr. Trump said again.