Well, maybe it has. There is no doubt the Iranian government was seriously discomforted by the blow of the assassination of, to multitudes and certainly the regime, a national hero. There is also no doubt that the unpredictability of the US Commander-in-Chief, Donald Trump, whose finger is on the buttons of the most powerful military in the history of the world, makes the Iranian leaders nervous.
They had to retaliate to satisfy the thirst for revenge of their followers, but they did so with cautious precision, to make sure they damaged nothing useful of the Americans, nor caused any casualties, even issuing an apologetic warning of their missile strike in advance. Having fired off the salvo they stood down their forces to a lower level of readiness, as a further signal that they did not want a real war.
There was of course a lot of rhetoric, even about abandoning the nuclear deal altogether, but Trump countered by saying that they would NEVER be allowed their own nuclear bomb. They knew what that meant. Trump offered talks, but on very aggressive terms. However experience shows he gambles with talks too, so Iran might well be able to begin the search for a way out of the not very good place they are now in.
Then, sadly, we have the catastrophe of shooting down the Ukrainian Boeing. All those innocent lives lost through some kind of military mess up. And many of the dead are Iranians. Frantic denials that the crash was caused by a missile caved in to the admission that this is indeed the tragic case. Iran owns this disaster and it has not helped its image. Trump will be feeling quite pleased with himself. The rest of us are left wondering why so many have to die for no real reason.