re: No, but on the other hand, do we want to be on the enabling end...
Failure to do anything may provoke a war to try and eliminate Sunnis. Iran is already well-armed and it is a big country with lots of people and nukes on the way. Countries help in their allies' defense, as long as our troops are not involved, I think this action is perfectly legitimate. Besides, if Iran is contained, it may see the error of its ways and negotiate. Think of arming the Saudis as a compromise between abandoning them and attacking the Iranians.
It would certainly be good public relations for us vis-a-vis the Sunnis all over the MidEast. They are already convinced we're favoring the Shia in Iraq over them..