I think it's telling that many of the goods on the list of tariffs imposed by the Chinese are subsidized.
Among mutually agreeing nations, they treat each others' entities equitably, and they do not treat each others' entities with less favor than they grant to entities of any other foreign nation.
I'm also a proponent of USA adopting an Import Certificate policy which is a unilateral trade policy.
I'm opposed to sovereignties presuming to intervene within others' domestic policies. What we or any other nations prohibit from passing through our national borders are domestic issues. That's the essence of the “most favored nation” concept.
With nations that we, the USA do not have such an agreement, or there's a breach of an agreement with us, our trade relationship should be conducted on an “ad hoc” basis.