There are opinions galore about international trade policy, especially for the United States. All are argued with passion but rarely with much evidence. The world economy has actually been growing faster for forty years than at any time since the eighteenth-century 'Commercial Revolution', which created both the first modern economies and the discipline of economics. And though all developed economics have been stagnant and in recession these last few years, the world economy is still expanding at a good clip. But no one asks, What are the facts? What do they teach us? What are the lessons, above all, for domestic economic policy?