According to a YouGov opinion poll, conducted on the day of the referendum on the United Kingdom's membership in the European Union, migration was the single most important issue for "leave" supporters, second only to a general preference for independence itself. But those who consider Brexit voters xenophobic misunderstand the nature of the problem. Thanks to the Commonwealth, the U.K. is one of the most open-minded countries in the world. Accusing the British, of all people, of being xenophobic is absurd.

In reality, the referendum's outcome reflects legitimate criticism of the EU's design, which is largely based on open borders toward the outside world and a combination of freedom of movement and the so-called inclusion principle internally. The EU should use this British vote of no confidence as an opportunity to change its migration rules fundamentally.

Former U.K. Prime Minister David Cameron was right to request more concessions in restricting the free movement of EU citizens. And, in its own interest, the EU should now implement what Cameron demanded: delayed integration of migrant EU workers into host countries' welfare systems. If the EU doesn't eliminate the current welfare magnet, it will disintegrate, because the migration issue is the most important for citizens in much of the union. Political parties that deny this are in for a nasty shock.