That had occurred to me, too. I guess I was hesitant to encourage it myself, as magic would make moderating roleplay much harder. Nations may use magic to solve their problems. For example, nation A needs more of B. They pray to C or use ritual D, and behold! They magically receive the B that they needed. It get even more complicated when it involves another player. What is to stop nation A to pray for a storm and sink nation B's attacking fleet? Does it make sense in the context of the universe? Is that fair? It would lead to many arguments about the rules of the game, rather than promoting the actual playing of the game.
I'd prefer to keep magic ambiguous. It COULD have been magic, but it could also have been something more conventional. For example, nation A prays for something to give them light. A research programme is set up, and is successful in developing the electric lightbulb. It could have happened because of the prayers, or it could have happened regardless. The most important thing is that it doesn't matter. It could have happened either way. There is a reasonable explanation from both sides.
Of course, that's just my position. While I'm not totally against it, there would have to be VERY specific rules surrounding it so that it couldn't be abused. It may end up just being too hard to moderate and manage and cause too much stress for players. That said, if 'magic' means things like the lightbulb example, I have nothing against it.
Maybe someone else has an idea about how it could work. I think this merits discussion.