I would argue they're not an American ally either. They have a few mutual interests around oil, economics, and, to a degree, terrorism, that's all.
Ok. Protectorate ? I think we agree anyway.
Except for the fact that what is being sold is legal, and can be used constructively - our military uses them - which meth can't, and that it's not being sold to children. Also the fact that most of the sellers are beyond our jurisdiction, as are most of the buyers.
Legal isn't moral. I challenge you to draw a moral line that both of us would accept. That would be interesting.
You want to draw one with other people's jobs and money, though, in order to salve your conscience.
Moral decisions can always have implications to good people. Your conscience seems to worry about them also.
See if you can draw a line we can both accept. I think you're up to it.