[nradov]

There won't be any invasion. No one has any appetite for that.

If a conflict with Iran comes it will be something like Operation Praying Mantis again plus strikes against key economic targets such as oil refineries. The Iranian navy and air force are largely defenseless against stand-off strikes. They would still be able to cause trouble by sponsoring terrorist groups, but all of their forces capable of projecting regional conventional power could be wrecked in a few weeks of sustained strikes.

(I am not suggesting that this should be done. Obviously everyone should look for ways to deescalate the situation.)

[InCityDreams]

>They would still be able to cause trouble by sponsoring terrorist groups,

The US country hasn't experienced 'real terrorism' (IRA, Baader Meinhoff, Red Brigade etc), especially on a sustained scale. It would indeed be a terrible thing for just a few lone wolves to pop over the border. Being such a vast continent the damage could be horrifying, not least of all for brown people. (Big nod to George Carlin).

[sudosysgen]

There is no Iranian navy or air force to speak of. It's an irrelevant force. Iran projects power using proxies and using missiles, none of which are easily disabled by stand-off strikes.