Today's world is full of threats. Two of the great bulwarks of our recent prosperity—the postwar European project and a (reasonably) well-functioning democracy in the U.S.—are under siege. Waves of refugees from the civil war in Syria are engulfing Europe and stretching to breaking the long-standing generosity of northern Europeans toward those in distress. We see horrors in the Middle East, faltering growth in China, and global warming. Substantial fractions of the populations in Europe and in the U.S. have seen little growth in living standards for many years, and they are disengaging from the political processes that have delivered so little for them. And across the rich world, growth rates of per capita income are falling, whereas almost everywhere, income and wealth inequalities are rising.