Why not?
Surely their Vets have the skills to do this. I know they do, because I know people who have imported horses from there, and the vets do know how to geld horses. And that’s more difficult than dogs.
So if spaying/neutering is not being done in Iran, it’s not the fault of the dogs, but of uncaring owners. Such people are everywhere; here in the USA we regularly read of animal ‘hoarders’ who have dozens of semi-feral pets, improperly cared for, and without spaying or neutering. But we read of them because they are reported, and prosecuted. If the whole society in Iran acts like our criminal dog breeders, that is an indictment of their society, not of the dogs.