Jeffrey Frankel, professor of capital formation and growth at Harvard University, previously served as a member of President Bill Clinton’s council of economic advisers. He is a research associate at the US National Bureau of Economic Research

Perhaps the most important task confronting the international order is enforcement of national limits on greenhouse-gas emissions, such as those that were negotiated in the 2015 Paris agreement. Carbon border adjustments could give these limits teeth, but fair application requires a revived World Trade Organization.