I think you can get away with enough in a PG-13 to suit the tone of this story. Watching the recent trailer you can catch a glimpse of what appear to be prisoners of war strapped upside down on troughs that will collect the blood from their slit throats. That’s pretty dark. And seemingly it’s an addition by the filmakers. It’s not an element from the book.
It seems that the ommission of jihad in the film’s marketing may have been a strategy to side-step any potential negative press in the lead-up to the film’s release. That seems wise given the way that American media likes to sensationalize every last detail that can be mined for potential outrage/eyeballs.
I guess we’ll see it and find out for sure.
The story revolves around spice but it’s not ABOUT spice.
In any case, it still doesn’t strike me as the kind of fictional drug that’s calling out for restrictions. It’s depiction can be mild enough to circumvent an unwanted movie rating and still not compromise the story.
Narcotics featured heavily in Batman Begins and that movie still had a PG-13. Again, I don’t see what about Dune’s story is crying out for an R rating in order to be true to the story.