There's a whole escalation you are forgetting. Iran will retaliate, to which the US wilk respond. That yields a situation where neither side can back out, but neither is putting enough pressure in the other to force them to stop.

The way through seems limited to:

- ground invasion - nuclear annihilation - regime change (no guarantee of success)

If the regime change doesn't work, the options are horrible. And remember that the current Iran regime is the result of a US backed regime change, which allowed radical elements to mobilize hatred against the US.