Such warnings do not amount to arguments against globalisation. As many of the economists in question are quick to note, the benefits of openness are massive. It is increasingly clear, however, that supporters of economic integration underestimated the risks both that big slices of society would feel left behind and that nationalism would continue to provide an alluring alternative. Either error alone might have undercut support for globalisation—and the six decades of relative peace and prosperity it has brought. In combination, they threaten to reverse it.