[I think we should pull our guys out and let those folks handle their own problems. Our boys are worth too much to expend on them.]
The point of having a military is to shield civilians from damage, not to cower behind borders or excuses. The time when cannon shot was the extent of enemy capabilities is long gone. Despite living hand to mouth and dealing with heavy economic sanctions, Iran has developed its missile capabilities such that they can hit targets thousands of miles away. It also has a nuclear program under way. The reason we need to prevent it from unifying the Muslim world into a single empire is because that would give the regime the financial resources to finally complete its missile and nuclear program. We don’t need a super-sized Persia with a nuclear triad.
https://en.wikipedia.org/wiki/Nuclear_triad
We could just pound their missile facilities to a pulp from afar.