How Britain Should Brexit

The U.K.'s new prime minister, Theresa May, has said that Brexit means Brexit. There'll be no second referendum. Leaving the European Union, she says, is her mandate.

That much may be clear -- but little else is. Britain's future relationship with the EU could take many forms. At one extreme is an acrimonious divorce that would leave the U.K. more separated from Europe's economies than many current non-members. At the other is something so close to EU membership that in economic terms Brexit would make little difference. The greatest danger for Britain and Europe lies in letting this uncertainty persist.