Mackubin Thomas Owens argues that we still need the Marines, because they’re not simply a second land army:
The current Marine Corps strategic concept envisions an expeditionary force in readiness capable of responding rapidly to the full range of crises and contingencies, primarily but not exclusively from the sea, with integrated and balanced air, ground and logistics teams. To this end, the Marines provide a responsive and scalable “middleweight” force that is light enough to get to where it is needed quickly but heavy enough — and with sufficient logistics support — to prevail against an adversary upon arrival.
Wait, why do we need the first land army, again?
I kid, I kid — but it certainly seems like land troops, troop transports, and close air support should all be integrated.
(Why do we have an Air Force, again?)
I am certainly of the opinion that, if there were no ban on the Army possessing fixed wing aircraft, that most of the Army’s attack helicopter fleet would be A-10s and AC-130s instead.
Yeah, I think the Army would be happy to have its own A-10s and AC-130s — and its own combat controllers on the ground calling in air support.