To my current understanding, James Matheson in his »The British trade with China« argued that China might have originally had the right to refuse trading with Britain, but that they lost such right by consenting- even tacitly- to the Opium trade. One passage that I interpret in the above sense reads:
Without discussing the question, whether the Chinese are absolutely warranted, in justice to their fellow-nations, in shutting out all the rest of the world from any participation in the benefits of so prodigious a portion of the most desirable parts of the earth,—even when that participation would be attended with corresponding advantages to themselves,—it may be contended that China has long since surrendered such rights, and is no longer in a position to enforce them, as against the British nation; that her conduct, during the last century or two, has amounted, not merely to a simple permission to us to carry on our trade with her, but has conferred upon us perfect rights, such as are accompanied by the right-of compelling the fulfilment of the corresponding obligations.
Thence stems my question:
Were there no instances before the mid 19th century Opium wars of a national state legally banning harmful imports? Were the above arguments more than facetious excuses by the legal standards of the time? Hadn’t Britain’s Empire in particular ever banned from import any product that they thought harmful and dangerous and no longer to be tolerated?
Let’s not go back to the time before the advent of Nations
Very rightly the term “national state” has been criticised. Unfortunately I am unsure how to better phrase this. My point is that Matheson (as far as I understand from my first reading) heavily draws upon Vattel’s “The Law of Nations” for defending the supposed British rights. I seek examples of states that have accepted “The Law of Nations” but enacted similar trade bans as the Qing did.