… and it’s not the US Marine Corps:
The marines are also concerned with their relationship with the U.S. Navy, which has now formed another ground combat force. To understand how this came about, you have to understand the relationship between the navy and the marines. The marines are not part of the navy, as they are often described. Both the navy and marines are part of the Department of the Navy. The Department of the Army and Department of the Air Force each have only one component while the Navy Department has two (the fleet and the marines) who are separate services that are closely intertwined. For example, the navy provides many support functions for the marines which, in the army and air force, are provided by each service. Thus navy personnel serve in marine units (wearing marine combat uniforms) as medics and other support specialists. In the army the medics are soldiers and the air force support personnel are all airmen. The use of the navy for support functions means a much higher proportion of marines are combat troops than in the navy, army or air force. This gives the marines a different attitude and outlook.
[After WW2,] the Marine Corps was no longer just a minor part of the navy, but on its way to being a fourth service. Over the next half century it basically achieved that goal. But in doing that, the navy lost control of its ground troops. Navy amphibious ships still went to sea with battalions of marines on board. But because the marines are mainly an infantry force, and the war on terror is basically an infantry scale battle, the marines spent a lot more time on land working alongside the U.S. Army.
In response to all this U.S. Navy began building a new ground combat force in 2006, staffed by 40,000 sailors. This is NECC (Navy Expeditionary Combat Command), which is capable of operating along the coast and up rivers, as well as further inland. NECC units have served in Iraq, and are ready to deploy anywhere else they are needed. The 1,200 sailors in the EOD (Explosive Ordnance Disposal) teams are particularly sought after, because of increased use of roadside bombs and booby traps by the enemy. NECC organized three Riverine Squadrons which served in Iraq. NECC basically consists of most of the combat support units the navy has traditionally put ashore, plus some coastal and river patrol units that have usually only been organized in wartime.
This new navy organization, and the strategy that goes with it came as a surprise to many people, especially many of those in Congress who were asked to pay for it. It came as a surprise to many NECC sailors as well. The navy even called on the marines to provide infantry instructors for the few thousand sailors assigned to riverine (armed patrol boat) units. The navy already had infantry training courses for Seabees (naval construction personnel) and members of EOD (Explosive Ordnance Disposal) teams. Now all that was combined in the Expeditionary Combat Skills (ECS) course which is conducted at a base in Mississippi.