How many children are needed for the generation replacement? With a decently low mortality, around 2.1. Which developed countries reach it? The US and only: 2.09. The second is Iceland with 1.92 - already below the replacement level. But did You know there are lots of supposedly high-fertility countries that also fall below the US benchmark?
Did You notice Iran in the list? Do You understand what does it mean? In 20 years, Iran will have no more cannon-fodder. On the other hand, have You noticed recent energy problems in Iran? Oil production is declining and export is going to dry, having the 2nd largest gas reserves in the world, Iran can't fulfill gas supply obligations to Turkey. Why? Think of decades of socialist mismanagement since the fall of shah. So even without any external interference Ahmadinejad has a choice between aggression now or death by starvation later. Time is on our side. Bar that nuke thing.