It could be that they have assessed that "hitting back" is not the smart response. An escalated regional conflict with a nation-state like Iran is a very different matter than a conflict against a terrorist organization like Hamas or Hezbollah, particularly one that could achieve nuclear breakout in a matter of weeks.Surprised the IDF hasn't hit back yet because you know there were multiple war games already run with targeting scenarios rehearsed. Makes me think the BM attack did some damage at the airbases. Both Israel and the Iranians have good OPSEC reasons for not sharing the truth, but eventually some BDA will come out. I doubt the IDF nor the US will share if they lost aircraft. If they did, which is looking more possible, then it could explain the delayed response.
Hopefully, cooler heads will prevail.