Be careful of the Iranians. Friends in disguise are worse than enemies. Let's not forget, it was what, 1971 war?, when the Shah of Iran put his army on standby to thrust into Pakistan? Who needs friends like these?
Energy? How much energy can they supply? Let me inform you, the rates they were offering, given that they are sanctioned, were close to the ones we would get from Qatar/Saudi/Kuwait for Oil and Gas. Now, why would we want this from Iran, when we can already bolster the trade with our old partners, who hate Iran anyway?
Killing our Border Patrol is a serious offence. There is a reason Pakistan responded back to India's aggression on LOC. Why am i advocating use of force? So they don't take our restraint for granted. FC lost one of it's men in the incident, what are you going to tell his family members? The normal, half baked story that Iran did this? At least with India we know what we are fighting for.
Think.
Drop a couple of JDAMs on their border outposts. The roar of the F100-PW200 engine from FL200, is deafening and defining enough.