The First Week

As the weekend begins and the reality dawns in the U.K. that it has voted to leave the world’s largest trading bloc, the rest of Europe will have their own questions to answer.

Amid fears that a “Leave” vote could further fuel populist and anti-establishment sentiment throughout Europe, the EU’s leaders could choose to take the unprecedented step of calling an emergency summit without British representation as early as Saturday, June 25.

The reason would be two-fold: send a message to Spanish voters who go to the polls June 26 that the EU remains strong; and to work out what to offer -- or, more likely, what not to offer -- the U.K. in areas such as free movement of people and access to the EU’s single market.

There will be divisions to overcome even without the British. In France, where opinion polls say the euroskeptic National Front may make it through to the runoff in next year’s presidential elections, President Francois Hollande will have cause to show the electorate that leaving the bloc carries negative consequences. Other leaders, such as those of the Netherlands and Denmark, where anti-EU feeling is also growing, may consider it more politically beneficial to offer support to Britain, their traditional ally.

Nations outside the euro area, especially those where anti-EU sentiment has been on the rise, such as Hungary, Poland and Sweden, could form a group of countries resisting any French and German attempts to move the EU in a more integrationist direction. With Britain’s exit, non-euro countries would lose their crucial partner -- they would represent only 14 percent of the EU’s gross domestic product.

David Cameron is scheduled to meet the other 27 EU leaders at a summit in Brussels the following week. It’s at this gathering that the prime minister is likely to trigger the EU’s Article 50 -- the never-before-used law that catapults nations out of the club.

That would set a deadline of two years -- until the end of June 2018, during which time the U.K. would have to negotiate its exit. Will Cameron want the U.K. to become like Norway or Iceland and maintain a close working relationship with the bloc as part of the European Economic Area? Or could there be another set-up that means the U.K. would have to trade with the EU under the World Trade Organization framework?

The First 100 Days

EU chiefs fear the referendum will spark similar demands across the continent. With elections due in the Netherlands, France and Germany in 2017, there’s reason to discourage others from following the U.K.’s course, and this could weaken Britain’s hand in negotiations. It could also divert the EU’s attention away from other issues, including Greek finances, the refugee crisis and tackling instability in Ukraine, according to Michael Leigh, senior fellow at the German Marshall Fund.