It is possible that something like the War of Assassins (Dune Universe, sorry) happens. Iran knows that it cannot openly strike civilian targets less it draws the ire of China and Russia nor could it match the US military in open combat, so that leaves Iran targeted assassinations in response, which their asymmetric units are perfectly fit to do. I'd be concerned if I were a high-level civilian admin or military officer in the US government. The US is not going to glass Teran in response to a high-level US official being killed either as again it would draw the ire of the World community. Expect Assinantions.