But France - on Friday commemorating its ambassadors to the United States - may have stepped in to disrupt that trust a little more than four years ago under former President Donald Trump, experts say.
While Biden was celebrating the new AUKUS agreement with Australia and Britain on Thursday, French officials expressed outrage at the agreement, which brought the country's 2016 submarine construction contract to Australia to an abrupt end.
"France's position has been very long ... it has been said that the US is allied with her, but the US is from Europe and is completely unreliable," said Georgina Wright, head of the European Program at Institut Montaigne, a non-profit think tank based in Paris.
Now, France can feel confident in that situation, he said, with Biden proving that "when (the United States) makes a decision, they will continue with it and will not think twice about their partners."
In France, the immediate reaction to the decision was swift and angry.
Describing the agreement as "a stab at the back," an angry French Foreign Minister Jean-Yves Le Drian said on Thursday: "We have built a relationship of trust with Australia, and this trust has been promised. This is not done between agreements."
In Biden, he said the President's decision "painful, foreign and unexpected" is a reminder of something that his former successor "did."
Trump's comparison is considered "a great insult" to France, Frédéric Charillon, a professor of political science at Clermont Auvergne University, said Thursday.
Within hours, Le Drian's harsh reprimand was translated into action, with the French calling for a gala in Washington that was scheduled to celebrate the 240th anniversary of the Battle of the Capes, during which the French sided with the United States in their independence struggle.
Pulling the plug on that group, however, was relatively small compared to the Friday afternoon increase in this communication agreement between Washington and Paris.
Wright said that although the navy itself would have angered French officials, it was the way the news was sent that was most likely to strike.
"The decision itself has been a major problem for the French industry," he said, "the country is losing $ 40 billion in contract. "You can't overreact to the industrial side," he said in a telephone interview on Friday.
However, Wright said, the main reason for France's relations with the U.S. was "the way the decision was made."