And legal production (on a huge scale) of drugs for sale to infidel nations.
It is not legal =>
https://en.wikipedia.org/wiki/Opium_production_in_Afghanistan
These drugs are then promoted by western dope smokers and libertarian drug activists. But muslims sit around smoking drugs all day too. They don't just export them. That's one reason nothing at all gets done in muslim countries.
Also, huge fractions of some muslim economies are devoted to cultivating and chewing a useless low-grade druggie weed called Khat. Yet another reason why these countries are basket cases.