Those who decry free trade are really opposed to innovation and change. Even ardent protectionists pay lip service to the value of invention and technological innovation. But they simply ignore the fact that technical change and an expanding knowledge base will compel significant disruptions in any society. Indeed, the disruptions are likely to be far more painful in a highly managed economy than in a more open one. New technologies have inherently unpredictable effects even in an economy without foreign trade.
Innovators largely succeed by destroying old markets and creating new ones.
The dream of managing trade is really equivalent to the problem of running a planned economy. Trade is merely the conduit through which information about a rapidly changing world is conveyed to the marketplace. There is no way to manage innovation without damaging a society's capacity to use and absorb that information. New technologies may create more jobs than they destroy but this is little comfort to those workers displaced by new innovation or competition, whether that competition comes from plants in Thailand or a newly opened factory in Silicon Valley. This is an embittering experience for the affected workers.