PARIS — Britain's vote to leave the European Union is a major repudiation of Brussels. That's the plain, brutal truth of the referendum organized by British Prime Minister David Cameron. It means the EU's second biggest economy after Germany will leave the European project. It means that one of the few EU countries to possess a substantial defense apparatus and heavyweight diplomacy is abandoning Europe.

No matter how you look at this sad business, it's a defeat for the EU, which is left weakened. The world now sees the bloc as an entity on the wane. You could think that this is an unfair assessment given Europe's track record. You could judge that Cameron had been a mediocre defender of the Union since the Conservative leader was fundamentally a Eurosceptic who rarely had a word of support for the EU. You could think that the British took a massive risk. But that's their own business now. They took a decision on their own, democratically. They're putting an end to 43 years of participation in a European project that didn't turn out too bad for them.

But our first thought is about the 27 countries that now comprise Europe. This is a historic blow for the EU. These 27 nations cannot simply ignore the consequences of Britain's exit. The worst thing to do would be to carry on as usual, an attitude that generates more skepticism for the bloc than enthusiasm.

The worst we could do today is to think this is just one catastrophic decision taken by Britons to withdraw into their island and that this decision won't prevent the European project from going on "as before." The most irresponsible position to take would be to blame it all on demagoguery, xenophobia and the lies that accompanied the Leave campaign.

You could, of course, denounce the easy nature of electoral populism, which, in this case, was cynically exploited by former London Mayor Boris Johnson. But that doesn't mean we should give up trying to understand the reflex of rejecting Europe.

Because if we do give in to this easy explanation, the EU will continue to undo itself with similar referendum votes and departures here and there. On the contrary, if we want June 23 not to mark the beginning of the EU's disintegration, the institution must understand that the British referendum forces it to reflect deeply on what it must become.

The issue of this new direction the EU must take won't be solved in a few lines. Let us carefully attempt to set out a potential path. Europeans aren't asking for a never-ending improvement of the single market, but they're not in a federalist mood either. They want more security in an unstable environment. They want controls on the Union's external borders at a time of significant influx.

In this day and age of "the democracy of immediacy," which the digital revolution established, Europeans want more European democracy. This means reinforced cooperation on defense and migration as well as a strengthened relationship among national parliaments on EU issues. This type of a "more Europe" thrust should reconcile ordinary citizens with the Union.

David Cameron took a massive gamble and lost. Consequently, he announced he would leave office in a few months. Now, organizing the divorce promises to be a long and complicated process. The treaties allow a delay of two to four years to negotiate UK's withdrawal from the EU.

The Parliament in Westminster is opposed to Brexit. Already, leaders from the Leave campaign are backpedaling. They say there's no rush. They want to drag out the process until 2020. Facing the unknown, they're scared. They see the tornado hitting the sterling pound and their city. They know a British recession is awaiting further down the road. And they know only too well that this was really an English vote, and that Scotland as well as a great part of Northern Ireland rejected Brexit. Now, again, it's the Kingdom's unity that is under threat.

In this troubled context, we on the continent must abide by fair play. But the English have made their decision. Out is out.