I think the bottom line here is that the Iraqi Shiites will have to let the Iraqi Sunnis know that either they immediately kill every Sunni who attacks Shiites, or all the Sunnis in Iraq will soon live in another country.
It’s not nice, but judging from the place, this seems to be the only two alternatives. Truthfully, the easier of the two would be the religious cleansing. If they leave voluntarily, they go to Jordan. If they resist, they leave by the vast and empty Saudi Arabian desert.
Let all the women and children move to the holy cities where they will be safe.