From what I've read about the previous strike and the Israeli campaign is that Iran's defences were surprisingly poor. I think they expected some losses, so will probably be confident of similar this time.
I do wonder what the plan is though. If its another limited strike on drone/WMD facilities/radar etc then how does that tally with help being on the way.
If its more about regime change, well this is now confirmed to be the biggest buildup of tactical aircraft since the second Iraq war so thats a start, but theres no sign of ground forces being mobilised.
Im assuming this is going to end up being another mass strike on infrastructure, that will then be dressed up as Trump liberating the Iranian people from oppression. And then onto the next thing.