Cyberpreparedness has to be our best defense, for a really long time.
Punch and counterpunch. For every action, there can be a reaction. Asymmetric warfare means that the response may not come by the same means as the first punch. There has been much speculation as to how Iran might respond — again, against the United States. There are plenty of places they could exert some force. It could come in physical attacks via the waters of the Persian Gulf, attacks from their many terrorist proxy organizations, or assassination attempts against military or civilian leaders.
Another potential means to deliver a blow is highlighted in this article, The Cybersecurity 202: Get ready for serious cyberattacks from Iran, experts say.
I do not think that just because nothing has happened yet, that we are free and clear of such cyberthreats. They have a character trait that we are in short supply of here in the USA, that being patience. They are in it for the long game and we would like it all just to be settled immediately.