A more supple EU would be harder to break apart and more viable in the long run. Macron is right to say that governments wary of integration should not impede more ambitious countries from moving ahead.

This more ambitious group simply needs to leave the door open for those on the periphery to join in later — if and when they meet a set of objective criteria for entering that inner circle.

Relieving countries from the duty of joining in certain policies could also help lower domestic political pressure.