What most folks don't or won't understand, is that under CITES treaty the receiving country may have greater restrictions then the exporting country. That's how USFWS, get to ban stuff.
CITES was originally intended to be a complete codification of the law relating to the international trade in endangered species. It was understood that Appendix 1 species might result in different rules in different countries - this is the inevitable result of requiring both an export permit as well as an import permit. But it was not contemplated that Appendix 2 species - which only require an export permit - would also be subject to essentially the same regime as Appendix 1 species at the whim of individual countries. If countries of import were allowed to restrict the importation of both Appendix 1 and Appendix 2 species, what would be the difference between the two appendices?
When certain countries, though, discovered that the treaty contained no particular prohibition on "higher" standards than what CITES required, CITES became a minimum, rather than the complete law.
This accounts for the current situation where the US and the EU, in particular, have added their own standards to CITES standards, refusing to allow the import not only of certain Appendix 1 species, but also of certain Appendix 2 species (and indeed any other species they decide to restrict).
Which leads to the question: What, in fact, is the impact of CITES? It seems to have become nothing more than an outsourced department for countries that don't particularly care to set up their own import/export regime. Everyone else pretty much doesn't care what CITES says. You have a quota from CITES - which they only give when sustainable off take can be demonstrated? Don't care. You have an export permit from the country of take? Don't care. We've signed a treaty saying that no import permit from us is required to import this species, so long as you have an export permit? Don't care.
There is one purpose it has served. While the US gives no legal weight to what CITES says in terms of quotas or permits, or in fact to what the science behind CITES says, it is more than happy to review all CITES paperwork with a magnifying glass, and to use any mistakes, material or not, relevant or not, to confiscate any animal being imported, while deflecting blame to CITES. So CITES has, for the US, become nothing more than a convenience target for blame when paperwork is incorrect. If the paperwork is correct, then the US will deny the import on its own, which means that it can then be blamed. But if you want to prevent the import of certain species, why take the blame unless you absolutely have to?