IRAN:
My guesstimate is that it would take the, ah, disappearance of a dozen people or less (maybe even as few as five) for the spark to finally hit the powder. Block deployment of IRGC support forces, and there would be a boom today.
One of the largest factors preventing the boom is our current Regency, which has gone to extraordinary lengths to protect the mad mullahs. And to fund them. This has been Obama policy from the start, in defiance of facts, logic, morality, and more.
Why? One can surmise either an incredibly naive belief in the stabilizing influence of Iran as a regional power, or that a significant number of our policymakers have been on the payroll of (or blackmailed by, or both) Iran, or its patron, China.