Why amphibious warfare is a combined operation

Should amphibious forces be a separate arm, or should they be organized as a combined operation?

They must be a combined operation, with naval firepower, air support, and ground forces coordinated through a dual command structure.

Amphibious warfare brings sea, land, and air systems into one operation. Exercises in Ceylon and on Britain's south coast integrated naval gunfire and air support with the troops going ashore. That interdependence drove a dual command structure rather than treating the landing force as an isolated arm. The same World War II-rooted arrangement later shaped British command practice in the Falklands War.