Exactly and that’s why there can not be enforcement of copyright laws with items being brought here to be resold because there’s no way to tell if something is lawfully made from a different country.
Sure there is. The first sale doctrine is limited in scope. The 9th Circuit, in a well reasoned opinion, has already held that the first sale doctrine does not apply to licensed software, and the Copyright Office has taken the position that the first sale doctrine applies only to physical materials—no application to digital. This approach seems rational and will likely be adopted by the courts.
So, putting all of this together, the question is pretty simple? Did you buy the book/movie from an authorized reseller? Are you selling that same copy in the US? If so, then you are OK. If not, then you’ve got a problem.
I will say, though, that I think the dissent gets the better of the argument. But I don’t think the opinion presents the policy risks that you propose.