Aircraft on the ground would be the targets. I doubt the SRBMs originated in the vcty of Tehran, and given US mil proclivities, the counterstrike wouldn't be ballistic missiles. Also no SAM is fired by 'accident'. Like SK in the 80's, if higher HQ thought you should have engaged, and didn't, you would probably be X'ed out. So you shoot when in doubt.
The other possibility was to implicate the US and get Russia involved. Clowns over thinking the problem.