I'm only interested in the "one reason" why the attack against IRI's armed forces(which by the way, was not a terrorist act) is idiotic for the backers of mullahs' regime. sorry.

It was horrible idea , beside killing people who were most likely  "sarbaz vazifeh" and not to mention by standards inclding women and childeren,  it gives a green light to a regime that is close to implosion to thighten its grip even harder on its opponent and last longer.

Furthermore what ever regime replaces this one, will most likely treat sepratists the same way! sorry folks we are not switzerland, nor do we have Luxembourg and Andora as our neighbors, within the geographical area od world we live in and its challanges, the out come is generally the same no matter who runs the show.