History teaches us that unfettered trade builds economies and brings the most people the most prosperity. While the world seems smaller and in many ways is, of course, it still contains enormously diverse cultures, skills, climates, natural resources and, most important, different stages of economic development. MFN status is outdated and embarrassingly misused. It is a worn out tool from another age. Trade is, or should be, about getting goods and services at the most economically sensible price.
Trade is still, as of yore, a source of information, learning, growing.
It should be no more restricted than information is. Living in fear of another's ability to compete is an admission of incompetence and in some ways, infantile. I don't see free trade as incompatible with industrial policy, as your Ricardo summary suggests. We may also require our bigger trading partners to shoulder a larger portion of the burden of their defense. Time is ultimately on the side of free trade but in the meantime we must do nothing to hinder it.