Iran won't seriously negotiate until it becomes apparent that the regime is losing its abaility to control the civilian population.
Start targeting police stations, jails, prisons, detainment facilities, etc. It is only after the elimination of the police and militias that there can be a popular uprising in Iran.
The current regime has been modeling itself after North Korea. All means of state control - police, media, militias, barracks, armories, etc - need to be targeted.