Well-placed geographically and politically between America and Europe, Britain has long marketed itself as the diplomatic bridge linking the two continents.
Most British prime ministers since World War Two have reached for the metaphor at some time or other to describe what they saw as Britain's essential and aggrandizing function in transatlantic relations.
When Europeans in 2001 were assailing President George W. Bush for his foreign policy plans, including pulling the U.S. out of the 1997 Kyoto Protocol on climate change, Britain's then-leader, Tony Blair, emphasized his desire to "build bridges of understanding between the U.S. and Europe."
Britain's role as a useful intermediary traditionally has been welcomed in Washington, although the role has often been resented in European capitals stretching back to the time of Charles De Gaulle, the French leader who blocked Britain from joining the then European Common Market, partly because he feared Britain would act as America's agent inside the bloc.
Post-Brexit and Joe Biden's foreign policy team is likely to have to switch roles and act as a diplomatic bridge for Britain to an estranged European continent, say analysts.
"I think you will see a concerted effort by the Biden team to engage London with Brussels, Berlin and Paris," says Damon Wilson, executive vice president at the Atlantic Council, a foreign policy think tank based in Washington.
A former senior director for European Affairs at the National Security Council in the George W. Bush administration, Wilson says Biden's foreign policy advisers will likely decide that to maintain coherence in the transatlantic alliance they will have to make sure "London is at the table with Brussels and the other main Western powers."
Britain's messy departure from the European Union, which saw more than four years of bruising, and sometimes petty, haggling, has left Britain's relations with its European neighbors in tatters. They are hardly in the mood to accept Britain as an American emissary.
And since Britain and its erstwhile 27 partners struck a final Brexit deal last month, defining, at least in the midterm, Britain's trade relations with the EU, ill-feeling has persisted.
This week a diplomatic row broke out between London and Brussels over the status of the bloc's ambassador in London with Britain's Foreign Office withholding full diplomatic recognition to the envoy on the grounds that the EU is not a sovereign state but an international body.
That breaks with the practice of 142 other countries that grant full privileges to the bloc's diplomats. Infuriated EU officials have dubbed Britain's move "petty."
British policymakers remain highly anxious about the future of Anglo-American relations post-Brexit, and now post-Trump. Britain's Boris Johnson at one time saw himself and Donald Trump as kindred spirits. Trump dubbed Johnson as "Britain Trump."
Proximity to U.S. power enhances British power - hence Britain's perennial eagerness to maintain the much-vaunted "special relationship" between London and Washington. Some observers say Britain has shown such an over-eagerness to engage that it could be construed as a sign of weakness, even desperation.
The fear in London is that the Biden administration will relegate Britain, seeing Germany and France as the more important transatlantic partners. President Biden's key foreign policy advisers, including his nominee to be the new U.S. secretary of state, Tony Blinken, a Francophone and Francophile who was raised in Paris, and Biden's national security adviser, Jake Sullivan, were disparaging of Brexit, viewing it as a strategic mistake by the British and one that would diminish Britain's usefulness to the United States.
Like Barack Obama, who openly backed Britain's remaining in the EU, Biden also disapproved of Brexit. In a speech in Dublin the day after the 2016 Brexit referendum, Biden condemned "reactionary politicians and demagogues" for Brexit, adding, "We'd have preferred a different outcome." Some former British diplomats have worried that Brexit "chickens will come home to roost" with a Biden administration.
President Biden himself has shown little liking in the past for Johnson, describing the British leader at a fundraiser during the primary race for the Democratic nomination "a physical and emotional clone of the president [Trump]."
Biden is said to have taken as much offense as Obama over a newspaper column Johnson wrote many years ago when he was mayor of London in which he accused Obama of being "part-Kenyan" and harboring an "ancestral dislike of the British Empire."
That column was written in response to Obama's moving a bust of the great British wartime Winston Churchill from the Oval Office. Trump returned the bust where George W. Bush had placed it, and Biden has now followed Obama's example.
Johnson's tune is different this time. In a statement, Downing Street said: "The Oval Office is the president's private office, and it's up to the president to decorate it as he wishes."
The fears of Britain's ruling Conservatives about how Anglo-American relations may unfold under a Biden administration were partly assuaged in November when Biden, after his election win, chose to phone Johnson ahead of talking with France's Emmanuel Macron and Germany's Angela Merkel. "Special relationship maintained as Johnson is first on Joe Biden's call list," The Times of London exhaled on its front page.
But British fears have not been banished completely. "The incoming administration of Joe Biden will seek to heal America's relations with allies in Europe and Asia," Robin Niblett, director of Britain's Chatham House, wrote in a commentary. "But Brexit Britain will have to fight its way to the table on many of the most important transatlantic issues, with the EU now the U.S.'s main counterpart," he added.
The British may be over-anxious, though, according to some analysts. A key policy aim of the new U.S. administration is to steady democracies roiled by unprecedented domestic political turmoil and challenged by authoritarian powers. Biden has said he wants to convene a global summit of democracies to forge common goals. Victoria Nuland, a veteran diplomat slated for a top job at the State Department, recently said: "It's time to stand up and defend it [democracy]."
The Biden administration appears to be in no mood to leave any democracy behind.
Speaking in December at an event in Washington, and before her pick to rejoin the State Department, Nuland said in her concluding remarks: "It's going to be very, very important for all of us to relink hands with the U.K. and ensure that London stays a strong global player and is well docked into the U.S.-EU conversation, the democracy conversation, and is really the global Britain that they have said they want to be."
The Atlantic Council's Damon Wilson says under the Biden administration "there will be a big and dramatic change when it comes to relations with Berlin and a very big emphasis on Berlin." "Germany will have a more prominent place in consultations," he adds.
But Wilson, who knows the Biden aides well, doesn't see that as necessary coming at the expense of Britain. "The UK is going to be valuable because it will be quicker, it will be more nimble" compared to the EU and Brussels. "You work with the British because they can move fast, they can do things and that expediency will make Britain still relevant," he adds.
Biden aides presented "strong and compelling cases about why Brexit would not be in American interests, but they won't hold Brexit against the British," he says.