Jake's actually right about the force projection issue, we can bomb about anything in particular we want to in Iran, but sending in a large-scale ground force is basically out of the question. Of course, thanks to the unmolested despotism in Iran and the brilliant intelligence decisions made by Jimmy Carter and Stansfield Turner thirty-odd years ago, Iran is a black hole as far as any HUMINT on targeting goes, so the prospects of fully taking out their program versus just damaging it and setting it back for awhile are not that good with bombers alone.
There are numerous reasons why conscription would not improve the situation, but I'll leave it with that so nobody falls asleep reading the extended-play version.