There is some deterrance of Iran with accurate medium range bms, cruise missiles and anti ship ballistic missiles. Everyone knows that most planes cant take off or land once the airbase runways are taken out.
However we know that Usa is not as free as it is powerful. They might sacrifice american citizens and american interests to secure a city cized country with no resources which is israel. An example is isis and alquada murdered many americans but usa indirectly supported these groups through client regimes like saudis to ensure israels hegemony. So having the potential to target and at least conventionally mutually assured destruction capability against israel is necessary. When usa finds an opening against Iran they will exploit it even if it costs them alot. Also It is better to not rely on others and better to think that in such scenario Irans partners like Russia will stay silent as well as China.
If a conflict breaks out with ballistic missiles especially against israeli targets it can make israel react with nuclear ballistic missiles even if Iran does not have them. Similar to Pak India the first salvo will be taken as nuclear exchange. So cruise missiles would be more effective for a limited war scenario to not to escalate into a ballistic missile exchange. usa bases -carriers are isolated military targets and ballistic missiles cant be directly categorized as wmds against them so they can be used as first strike deterrant option.
I think cruise missiles against israeli underground bunkers would be more effective for first strike option. Depleted uranium rods in cruise missile warheads would ensure better bunker busting ability. Thus more deterrance.
