And morally, why should we provide some other country?

Enlightened self interest. If we want less heroin in our country, it's in our interest to provide something better for people in other countries to do than grow than heroin poppies. There's a lot of stuff to grow, I'm pretty sure something can be found that doesn't violate the sacred texts.

Otoh, Synthentic opiods may be cheaper and easier than harvesting heroin poppy, so maybe the specific problem of heroin export is solved, but not in the intended way.