Critics feared it would plunge the Middle East into a wider war. That doomsday scenario has not come to pass, at least for now: Iran made only symbolic retaliation against America; soon after, a ceasefire ended the fighting between Iran and Israel.

DUBAI - Iranian authorities have arrested hundreds of people and executed half a dozen in a sweeping security crackdown that analysts say is aimed at exerting control after a brief but punishing war with Israel exposed Iran’s deep infiltration by Israeli intelligence.