Darius did make a proclamation to punish those involved in the Ionian revolt, but the Achaemenid Empire was suffering from all sort of revolts, and historians generally conclude that the invasion of Greece was motivated by the opportunistic expansionism of the Persians. Any punitive action taken against the Greeks had to be weighed against an occupation. It’s often less than sensible to provoke an occupied territory with unnecessary punitive approaches because it compromises the integrity of the occupation.
Of course, that’s a cost benefit analysis; sometimes it pays off to instill a measure of fear. I disagree that polities generally take an eye for an eye approach to war, though; they most often act in their self-interest. What that is generally reflects the conditions of their environment. Sometimes it’s capitulation, sometimes it’s retaliation, sometimes it’s joining the guys that just beat the snot out of you to help them beat the snot out of everyone else. In every instance though, those actions are calculated. Very rarely do polities take action that would compromise their self-interest unless substantially provoked. Obvious exceptions are when a polity is so overwhelming that they don’t risk repercussion for their vengeful actions; Alexander burning the palace at Persepolis is a great example of that. To be fair though, he was probably just drunk.