These 7 photos show how the Marines take a beach
If the US had to assault a beach today, the assault would have to be conducted from over the horizon in order to avoid being targets for anti-ship missiles launched from several miles inland. This would push amphibious ships back approximately 15-20 nautical miles, stretching the range of current AAV range, which would work in conjunction with assault aircraft and helo's. Factors to consider are sea state, enemy defenses, maneuverability of nearby enemy armies, range of landing craft, potential casualty rate, availability of logistical support upon landing etc. All of these factors come into play when launching an amphibious assault, and each and every factor has an acceptable "failure rate", which may or may not become a limiting factor with respect to launching the assault.
The actual assault would have a long timeline, and would look something like the following:
0100: Begin aerial and missile bombardment
Photo: US Air Force
0200: Launch amphibious landing craft (AAV's)
Photo: US Navy Mass Communication Specialist 2nd Class Katerine Noll
0415: Launch helo assault and gunships e.g., V22 Ospreys, Super Stallions and Cobra's.
Photo: US Marine Corps Cpl. Michael L. Haas
0455: AAV arrival at surf zone outside of target objective, halt missile and aerial bombardment.
Photo: US Navy Photographer's Mate 3rd Class Julianne F. Metzger
0500: AAV' assault beach and begin suppressing fire on target where necessary with accompanying infantry.
Photo: US Marine Corps Staff Sgt. Leo A . Salinas
0505: V22 and Super Stallions drop reinforcing infantry battalion.
Photo: US Air Force Tech. Sgt. DeNoris Mickle
0600: Beach secure, begin landing heavy armor and logistical support.
Photo: US Navy Photographer's Mate 3rd Class Laura A. Moore
William O. Scarf writes on Quora.com.