Bangladesh, Oct. 19 -- A good political leader needs vision, integrity, strong communication skills, empathy and the courage to make difficult decisions in the national interest. Leadership is tested most severely during periods of uncertainty, when confronting uncomfortable truths matters more than protecting political reputations. For Britain, Brexit has become such a test. With economic growth struggling, international security deteriorating and public confidence in leaving the European Union weakening, the case for rebuilding closer relations with Brussels deserves serious consideration.

Nearly a decade after the 2016 referendum, Brexit has failed to deliver many of the economic benefits its supporters promised. Economic research sug...