The decision of LACM over BM for the US navy was made in the 80's and given the accuracy of BM and weight requirements compared to range on top of safety issues it was a rather sound decision.Diego Garcia should be handled with a Khorrmashahr variant. Count on a Salman based ICBM, not the Zoljanah.
What about the U.S setting up a bridgehead near the place it wants to attack and use BM's?
They chose LACM because they had no BM that could do that job back then.
FYI their new "Hypersonic weapons", are basically BMs.
Midgetman or Salman are just much more advanced technology. Similar to Shahab-3 vs. Khorramshahr.
Even if you create a bridgehead somewhere near enough to an enemy territory you wish to invade, how many BM could you possibly deploy and launch from a location before that location is targeted? And how many BM could you possibly deploy to make up for an Airforce?
And how are you gonna counter moving targets at sea, in the air and on the ground?
How do you propose to defend against incoming helos? ships? Aircrafts? Armored Battalions?... And how could you possibly defend your own invading force without Aircrafts?
When your defending your own territory you can afford the logistics of having a vast BM force to counter most fixed targets by spreading them across your territory but for a country that carries out invasion after invasion the logistics alone becomes a rather impossible task
How are you gonna get a foothold in enemy territory to create a beachhead when you can't defend your fleet? How far would this bridgehead be for your intended beachhead?
Right now US has over 30 bases within 300km of Iran that can be considered a bridgehead. How many missiles at each of these bases are you gonna deploy and how many missiles could these locations launch before becoming a target of Iranian retaliatory attacks?
Missile can at best make up for the strike capabilities of an Airforce and that's it! They CAN NOT make up for every aspect of an Airforce! From escort to intercept to transport to attack....