- Obama had spoken out forcefully in favor of the UK remaining part of the 28-member EU
- Biden acknowledged White House disappointment at the result Friday
Washington (CNN)Britain's vote to leave the European Union Friday left the United States confronting a threat to the strength and cohesion of both its closest historical ally and a 70-year transatlantic partnership that has been the bedrock of Western peace and prosperity.
The outcome of Britain's referendum instantly pitched an already weakened Europe into a new crisis, opening the possibility that other member states could choose to leave the E.U. and create new headaches for Washington.
American leaders on all sides of the political aisle Friday expressed respect for the decision of British voters and vowed to stand with America's "special relationship" ally Britain and the diminished European Union once both partners have finalized their divorce -- a period that could take years.
But there was no hiding the concern behind the scenes as the shockwaves rippled through the EU, a body that has been vital to American foreign policy initiatives in recent times, including the drive to a nuclear deal with Iran and attempts to punish Russia for its incursion in Ukraine.
UK referendum: Full coverage
- Why do the Brits want out?
- How Europe should respond
- Why the U.S. is freaked out
- Does this mean Trump will win?
- Results map tells a big story
- Could this man be next UK PM?
- Anger in bedroom, joy on streets
- Reasons why Brexit could be good
- Could Scottish independence be next?
- Britain voted 'Leave,' what's next?
- What will Brexit mean to me?
- World markets in crisis after Brexit
President Barack Obama, who felt strongly enough about a British exit or "Brexit" to travel to Britain in April to warn it could not expect special treatment on reaching a free trade deal with the U.S. if it left Europe, offered a rote assurance that nothing would actually change between London and Washington.
"While the UK's relationship with the EU will change, one thing that will not change is the special relationship that exists between our two nations," Obama said during remarks at Stanford University in Palo Alto, California. "That will endure."
But Sir Peter Westmacott, until earlier this year Britain's ambassador in Washington, contradicted the idea that nothing would change in the U.S-British relationship.
"I feel very sad," Westmacott told CNN's Christiane Amanpour, adding that Britain after Brexit would be "less influential in the world, in the European Union, in NATO and the Security Council and a less significant ally for the United States and many others."
"I think we are going to have to paddle even harder with our diplomacy ... to ensure that we continue to ensure that we have our place at the table."
Vice President Joe Biden, the administration's less-filtered voice, was more clear about White House disappointment at the result when he spoke to the issue on a trip to Ireland Friday.
"I must say we had looked for a different outcome," he said in Dublin. "We preferred a different outcome."
For the United States, the possibility that the populist, isolationist victory of the "Leave" vote translates into broader political victories for the movement in Britain and elsewhere in Europe, could mean Washington could eventually find itself straining to get help it has relied on from allies. The UK vote has triggered calls for similar referendums in France, Sweden and the Netherlands, while populist governments already hold power in Greece, Poland and Hungary.
If the Brexit vote results in a domino-like ripple of similar votes or political victories, the experiment of a united Europe could come to an end. It would make the continent less able to help the U.S. push back against Russian assertiveness along Europe's eastern seam, analysts said.
The United States has traditionally relied on an engaged Britain, alongside other allies Germany and France, as a way to ensure its interests are taken into account on the top table of Europe -- and now faces the prospect of one of its most influential allies leaving the block and diminishing its clout.
For the UK, it's not just the EU exit that could cause Britain's influence to wane. If Europhile Scotland now holds a second independence vote, the power of Washington's old ally could be further splintered.
Britain has been a traditional U.S. partner on efforts to stabilize Afghanistan and cooperate in the Middle East on issues ranging from Iran's nuclear program to Israeli-Palestinian peace and the scourge of ISIS. One outcome of the Brexit vote could be "less help from the UK and other NATO allies in the Middle East and elsewhere," said Daniel Serwer, director of the Conflict Management Program at the Johns Hopkins School of Advanced International Studies.
In the short term, a distracted UK, led by a lame duck leader following Cameron's decision to step down, might not have the same capacity or inclination to take on global challenges.
And the economic hit the UK will take as it extricates itself from a market that accounts for 44% of its exports could leave it with fewer resources to do its share. The U.S. is itself already feeling the aftershocks -- American stocks were down more than 600 points at the closing bell Friday afternoon.
Altogether, that could mean a smaller Britain, less able to meet its defense commitments, and it would pose problems for the future of the U.K.'s independent nuclear deterrent, which is based in Scotland and is opposed by the ruling Scottish Nationalist Party.
It could also deepen the U.S. perception that took root under the Obama administration that the U.S. "interests lie more in Asia than in its traditional Atlantic sphere of influence," according to Sebastian Mallaby, a senior fellow at the Council on Foreign Relations, writing in The Washington Post.
Still, American political figures stressed their commitment to the UK despite the change.
House Speaker Paul Ryan, a Wisconsin Republican, tweeted that "the UK is an indispensable ally of the US, and that special relationship is unaffected by this vote."
Sen. Richard Burr, the North Carolina Republican chairman of the Senate intelligence committee, said that "while there will be a great deal of discussion in the coming days and weeks about what the 'Leave' win means for them and for us, our friends and allies in the UK should know this: we respect their decision, and we stand by them, just as they have always stood by us."
The President spoke with British Prime Minister David Cameron and German Chancellor Angela Merkel on Friday to convey the U.S. commitment to both of them, saying afterwards that the EU will remain a "vital" U.S. partner, alongside NATO.
"Our shared values including our commitment to democracy and pluralism ... will continue to unite all of us," Obama said, repeating a common theme in his addresses as criticism of immigrants and religious minorities has featured in the presidential campaign.
But the administration is also looking to adjust to the new reality.
"What was said was we believed in a strong UK voice in a strong EU and that was our position in advance of the referendum," said State Department spokesman John Kirby. "The people of Great Britain have spoken and they want the UK out of the EU that's beyond dispute, and so we now have to move on."
Amid the widespread shock at Britain's decision, Washington is beginning to size up the implications.
"For sure," said Deputy Secretary of State Tony Blinken Friday, "it's going to be a complicated process."
CNN's Kevin Liptak and Jeremy Diamond contributed to this report.
BUT, on the other hand, DONALD TRUMP is exulting:~~~~~~~~
Trump on Brexit: America is next
By Stephen Collinson, CNN
Updated 0846 GMT (1646 HKT) June 25, 2016
Washington (CNN)British voters just shattered political convention in a stunning repudiation of the ruling establishment. Donald Trump is betting America is about to do the same.
Voters in the UK did more than reject the European Union and topple their pro-EU Prime Minister David Cameron in a referendum Thursday.
UK referendum: Full coverage
They also set off a cascade of events that could spark global economic chaos, remake the Western world, reverberate through November's presidential election and challenge U.S. security for years to come.
The referendum campaign -- just like the U.S. election -- has boiled with populist anger, fear-mongering by politicians, hostility towards distant political elites and resurgent nationalism, and exposed a visceral feeling in the electorate that ordinary voters have lost control of the politics that shape their own lives. Its success raises the question of whether those forces will exert a similar influence in America in November.
The presumptive Republican presidential nominee, who arrived in the UK to visit his Scottish golf courses just as the referendum result was announced, declared Friday that the U.S. is next.
"Come November, the American people will have the chance to re-declare their independence. Americans will have a chance to vote for trade, immigration and foreign policies that put our citizens first," he said. "They will have the chance to reject today's rule by the global elite, and to embrace real change that delivers a government of, by and for the people."
Indeed, British voters delivered the kind of crushing rejection of the political, business and media elites that Trump has been railing against.
The Brits also snubbed President Barack Obama's warnings against voting to leave Europe and risked triggering a global recession that would weaken already sluggish U.S. economic growth and dampen the hopes of his chosen successor, Hillary Clinton.
In her first reaction to the news from Britain, Clinton immediately took a swipe at Trump, though not by name. She called for Americans to respond to the vote by pulling together "to solve our challenges as a country, not tear each other down."
Clinton also noted the global economic risks of the UK referendum, saying in a statement: "Our first task has to be to make sure that the economic uncertainty created by these events does not hurt working families here in America."
In a particularly striking development, UK voters completely disregarded warnings from elite voices of the consequences of tearing the political system that has largely delivered peace and prosperity since World War II.
Similar warnings have been heard in the U.S. election -- especially from Clinton and establishment politicians who fear Trump's "America First" stance would send shockwaves through the global system and see America pull back from its role as a guarantor of Western security.
But in the UK this week, outsider politicians seem to have carried just as much weight with many British voters as more conventional fact-based arguments. World authorities like the IMF for example warned about the consequences of a Brexit -- but voters went ahead and voted to leave anyway.
Speaking to CNN, former British Prime Minister Tony Blair described the Brexit result as a "big experiment in insurgent politics."
He said the centre-left and centre-right needed to "rediscover radical, powerful answers in a climate driven by anger ... a revolt against what is seen as established wisdom, but what is actually people making difficult decisions in difficult circumstances."
There are, of course, several key differences between the British referendum and America's looming election.
The UK vote was mostly about delivering a stunning and final blow to the country's long and reluctant marriage with Europe and turned on a host of local factors including extreme Euro-skepticism within the governing Conservative Party, distrust of European politicians and institutions and disenchantment with Britain's reduced place in the world.
But in a larger symbolic sense, the referendum result, narrow as it was -- 52% to 48% -- demonstrated the potential of voters to wield a stunning shock to the political system that can shatter the logic and assumptions of conventional politics.
There's no guarantee that American voters will show the same kind of rebelliousness and willingness to leap into the unknown in November as a slim majority of Britons did on Thursday. And the U.S. system of state-by-state races and an electoral college could mitigate against some of the grassroots anger that exploded in a binary "Leave" or "Remain" vote in Britain.
But events in Europe must trigger at least some concern among Democrats.
Pollsters in the UK underestimated the fury of grassroots voters outside metropolitan areas in a way that could be mirrored in the United States, where Clinton now enjoys a lead in national surveys.
Furthermore, "Brexit" forces triumphed partly because the Labour Party could not deliver its traditional working class voters in some big post-industrial cities for the "Remain" campaign, despite the support of party leaders.
It is not a stretch to wonder whether the kind of political message that was so powerful in the referendum -- featuring a harsh critique of free trade and a demands to "take our country back" -- could prove just as effective among blue-collar workers in rust belt states in the United States.
Certainly, it's a message that Trump has been hammering with success all election season and is at the center of his claims to be able to remake the U.S. electoral map. And the billionaire has consistently bested Clinton when voters are asked who is best equipped to handle the economy.
The immediate stock market contagion unleashed by the referendum across the globe represented the worst equity carnage since the start of the Great Recession in 2008.
If the losses prove short-lived, the impact of the referendum on the U.S. economy and politics could be temporary.
But if "Brexit" ushers in a period of economic volatility across Europe that begins to squelch growth, the U.S. economy could be badly affected -- complicating Clinton's bid to pull off the tough assignment of winning a third consecutive White House term for the Democrats.
Trump would meanwhile seize on any slowdown in the U.S. precipitated by Brexit to argue that Obama's economic management is a failure and it is time to try something new.
But there are also warning signs for Trump.
Though he was quick to claim a share of the credit for the British political earthquake -- placing it in the context of a revolt against global elites in which he sees himself as a major player -- a prolonged period of world turmoil could also work against the billionaire former reality star.
Such an environment could bolster Clinton's claims that a crisis is no time to choose a president who has no experience of governing and that her pedigree as a former secretary of state and relationships with leaders all over the world are a perfect fit for a perilous moment.
The Democratic presumptive nominee made that argument in her statement: "This time of uncertainty only underscores the need for calm, steady, experienced leadership in the White House to protect Americans' pocketbooks and livelihoods, to support our friends and allies, to stand up to our adversaries, and to defend our interests."
Her campaign later issued a fundraising appeal with that message, writing, "No matter what the collective wisdom of our political punditry has to say between now and November, Donald Trump has a real chance of winning this election."
Clinton's campaign worked hard to demonstrate a contrast between Clinton and Trump as potential leaders in a time of crisis. The Clinton camp also sought to downplay similarities between the seething political scenes in the U.K. and the United States.
"It is important that we recognize that this American election is about what is happening here in America not what is happening in Yorkshire or in Cardiff," said Clinton's senior adviser Jake Sullivan on a conference call.
Sullivan also rejected the idea that Clinton could find herself overtaken by a similar populist tide in November, saying she had spent months on the campaign trail and was intimately familiar with the difficulties facing many working Americans.
The possible economic consequences of Brexit in the short-term could be dwarfed by the geopolitical shakeup that is now looming in the years to come.
Britain's referendum has already set off calls in Europe for similar separation votes in other Eurosceptic nations, threatening to dismantle the economic and political union that has been a pillar of transatlantic stability for 70 years and been a crucial partner for the United States.
As the U.S. faces challenges to its power in Asia from a rising China and in Europe from a recalcitrant Russia and in the Middle East from a motley group of insurgent forces, Washington can hardly afford the splintering of its co-guarantor of Western security.
In addition, the referendum looks likely to result in the fracturing of America's closest historic ally, the United Kingdom -- a factor that could be a diplomatic nightmare for the next president.
In the hours after the vote, Scotland's First Minister Nicola Sturgeon announced plans to draft new legislation to allow a second independence referendum north of the border after pro-EU Scots narrowly voted to stay in the United Kingdom in 2014.
Though a Scottish referendum may not take place for years, it will revive questions about a neutering of British military power and the fate of Britain's Scotland-based nuclear deterrent -- which nationalists opposed and is part of NATO's security infrastructure -- that the next U.S. president will be forced to grapple with.