We share a common planet, and the world has learned the hard way that we have to get along and work together. We have learned, too, that cooperation can benefit all.

If Trump wants to withdraw the U.S. from the Paris climate agreement, the rest of the world should impose a carbon-adjustment tax on U.S. exports that do not comply with global standards.

Europe can't rely on a Trump-led U.S. for its defence. But, at the same time, it should recognise that the cold war is over - however unwilling to acknowledge it America's industrial-military complex may be.

Joseph Stiglitz Quotes