While broadening the choices open to consumers, it can simultaneously deny a producer the security of a guaranteed home market. But any policy of protectionism designed to provide that security will do harm to consumers. Too often we see the good that restricting imports might do for a few and ignore the very real injury which would be inflicted on the many. There simply is no escaping the fact that protectionism as an idea does violence to the logic of liberty, peace, and economics. For the true libertarian, the liberty argument against protectionism ought to be sufficient refutation by itself.
Humans have a natural right to be free from arbitrary interference in their peaceful affairs.
Trade restrictions disrupt and punish a peaceful, voluntary, and mutually-beneficial activity. The legitimate function of government is to prevent and punish violence, not to initiate it. Protectionism must be regarded as a manifest violation of liberty, and its advocates must tell us what earthly goal their policy serves that is greater than human liberty. As long as people are free to reap the benefits of trade, they have a direct and immediate interest in tranquil relations. But raise the tariff and close the borders, as was done in the 1930s, and relations deteriorate.