We're not going to war with Pakistan. They're strategically located, they've been a solid US ally going back to the cold war, oh, and they've got a few nukes at their disposal as well. Iran, on the other hand, is the biggest thorn in our side in the Islamic world.
That would be another completely pointless US based siege/attack, here comes Afghanistan part 2
I think this would completely destroy your economy, especially since it's totally uncalled for, there's no real
threat coming from there, despite what bush might have you believe.