The U.K.’s departure means that it will become more difficult for the rest of Europe to financially support profligate countries like Greece, said Valliere, because of financial constraints and fears of a political populist revolt at home.
Although British Prime Minister David Cameron has already announced his resignation, Valliere said that German Chancellor Angela Merkel, already an unpopular figure in Europe because of her calls for austerity, will face additional pressures at home.
In the U.S., the “Brexit” will also have implications for this year’s presidential election and for policy making.
For one thing, Brussels and Washington are roughly analogous, said Valliere, with public revulsion towards distant bureaucrats fueling support for outsider candidates and causes.
Donald Trump, who happened to be in the U.K. on Friday, stands to gain from the result, said Valliere.
“Trump has an opening,” Valliere said. “A seething resentment of the establishment is bubbling up everywhere, and this week’s turmoil, from the floor of the House to the financial markets, only helps him.”