However, the Marine Corps insists that such a capability is needed so let’s address what I consider the most likely amphibious assault scenario: a port seizure. The Marines refuse to discuss it or even consider the possibility so we’ll do it for them.
Short of a massive, multi-year buildup there is just no possibility of logistically sustaining a sizable invasion across a beach. That only leaves the option of seizing an existing port to support the unloading of cargo ships at a rate sufficient to sustain a major invasion. The astute historian will note that this is exactly what the objective of the WWII Normandy D-Day assault was. Since all ports are associated with city structures and infrastructures, the roads leading to and from the port will prove every bit as critically important for quickly dispersing the unloaded supplies as the port itself.
Here are the main aspects of an amphibious port seizure and the more detailed points associated with them.
Port – The port, itself, must be seized, obviously. The key is to seize it as quickly as possible, to minimize the time the defenders have to destroy the facilities such as cranes, piers, docks, ramps, and warehouses. The best method of seizure is an initial airborne assault to quickly place infantry in and around the port to seize the facilities. Simultaneous with the airborne assault must be an amphibious assault with heavier weapons, artillery, and armor to relieve the airborne troops and secure and defend the port.
Roads – Airborne troops should also be used to seize key roads leading in and out of the port so as to prevent immediate counterattack. As with the port, additional amphibious troops will be required to relieve the airborne troops and secure and defend the roads.
Warships – It will be necessary to operate warships in the closed and congested waters of the harbor/port to provide cruise and ballistic missile defense, gun support, and counterbattery fire. This is completely contrary to current Navy doctrine and will require new doctrine and tactics.
Mine clearance – It is hard to imagine that any modern port will not be heavily defended with mines. Given that speed is the key to successful assaults, in general, and seizure of an, at least, semi-functioning port, mine clearance must be accomplished extremely rapidly to allow warships, supply ships, transports, and repair vessels access to the port. For example, the WWII D-Day assault involved hundreds of minesweepers to achieve the necessary clearance in a combat-useful time frame. Currently, we utterly lack the capability to perform this chore.
C-RAM (Counter-Rocket, Artillery, and Mortar) – Being a known, fixed location, a seized port will be subject to intense mortar and artillery fire. Mobility, the mantra of modern militaries and the presumed solution to mortar and artillery fire, does not apply to seizing and holding a port. Our forces will be static and fixed. Uh, oh! That’s an operational and doctrinal oversight! C-RAM protection will be required.
Missile Defense – Aegis warships will be required to establish a protective missile defense umbrella over the port. This may be complicated by large buildings obscuring the radar view of the ships and may require an offboard, networked sensor. However, we currently lack a communications and network system that is proven capable of functioning in the face of electronic and cyber countermeasures.
Road Defense – Roads are simultaneously the avenue for enemy counterattacks and the means of moving supplies out to the main invasion effort. Defending the road system, especially early on, will be manpower (infantry) intensive and require large quantities of armor for mobile defense.
Repairs and Rebuilding
Barring some incredibly good luck, the enemy will likely destroy the port facilities to a very large degree. We will need to rebuild most of the facilities. We will need the ability to unload with only minimal port support while repairs are on-going. We will need to rebuild under fire. Who will do this? How will they be protected? What equipment is needed? Are we trained to rebuild port facilities while under fire (hint: we aren’t)?
Loading/Unloading Operations Under Fire
Since the port’s cranes will have likely been destroyed, we’ll need ships with their own large cranes as a stopgap unloading measure until we can rebuild facilities. A dedicated crane ship or two would also come in very handy. We’ll also need large numbers of fork lifts, trucks, etc. for quickly moving the unloaded supplies out and to the invasion force. Initially, all of this will occur while under fire. Are we prepared and trained to unload and disperse supplies while under fire? Are we prepared to disperse supplies very quickly so as to avoid the buildup of large stockpiles (meaning very attractive targets)?
The key, and the entire point, to seizing and using a port is the ability to quickly disperse incoming, unloaded supplies out to the main invasion force. The dispersal (meaning transport of supplies) will be complicated by the fact that there will only be one or two routes and those routes will be known to the enemy and, thus, subject to continual attack. Are we prepared to fight our supply convoys through? Do we have the necessary doctrine to secure roads, establish defended zones around the roads, and protect convoys? Are we mentally prepared to inflict the degree of collateral damage on the surrounding areas that will be required to clear them of enemy forces? Ironically, improvised explosive devices (IEDs) and mines, the bane of our Iraq/Afg efforts, will be a non-threat in this scenario since, presumably, we’ll kill anyone/anything even remotely approaching the transport roads – unless, you know, we try to fight a zero-casualty, zero-collateral damage type of war which would be incredibly stupid but is exactly what we’ve done in Iraq/Afg.
Other than for occasional small scale raids, over the beach assaults are neither feasible nor operationally warranted. Port seizure, however, is mandatory. There is simply no other way to logistically supply a modern, major assault force with the required volume and tonnage of supplies. I believe that this is, or should be, the Marine’s core mission.
It is obvious from the preceding discussion that port seizure requires a specific and specialized force with specialized equipment, doctrine, and tactics – almost none of which exists, today. Being amphibious, the Marines are ideally situated to provide much of this capability although it would require a complete rethinking of their purpose and a complete rebuilding of their force structure.
The issue of airborne troops, alone, is an interesting one. Would these troops come from the Marines or from existing Army units? Would the preferred airborne delivery be parachuting or helo insertion? These are the kinds of questions that need to be explored in realistic exercises. Unfortunately, to the best of my knowledge, there has never been a port seizure exercise by the US military in recent decades.
If port seizure is as important as I believe it to be then we need to begin developing the force necessary to do it. If one would argue that port seizure is not important then I need to hear how we’ll logistically support a major invasion force.