From the January 10, 2011, New Yorker:
Should America maintain the Marines as a separate branch? Or would it be more efficient to subsume the Marines’ functions into the Army and Navy? Would we save money by eliminating the Marines as a separate branch?
Hard to say.
I suppose having the Marines separate adds some cost in duplication of command structure and perhaps some material.
That said I kind of like tradition and see no particular reason to toss them as a distinct entity. I will presume the cost savings are not considerable if all you are doing is maintaining the same capabilities under the Army or Navy (but I do not know).
As for never needing to storm Tripoli again all I can say is how do they know? The military has been known to make poor decisions in the past such as no guns on fighter jets or no cleaning kits for machine guns because the new world order didn’t need those things (they were dead wrong in both cases).
That said I am a guy who misses the old battlewagons which, of course, would be great if anyone had to storm a beach again. Maybe the world does not need them considering their cost. They sure scared the willies out of people though which has a value all its own.
I thought they were part of the Navy, actually.
Other than a) guarding embassies & b) getting thrown into really nasty firefights, do the Marines have a distinct mission?
An integrated dynamic self contained force able to put boots on the ground anywhere in the world within a week with the capability to protect them. Projection of force, threat, is what the marines are all about. Aircraft carriers cost a lot more and do a lot less.
If our strategic aims are to maintain some kind of hegemony then I’d say the Marines are the one wing of our military we can’t sacrifice.
The Marines have evolved to a multi-function special forces unit.
And who would fly Obama when he needed a copter ride 
But why can’t the Army and Navy take over those functions?
Don’t forget the Marines are a semi-elite force. The standards of training are higher and not everyone in the military would meet those standards.
It’s a good tiebreaker too. If it’s a operation that would cross from traditional army/navy and even air force rolls, it could go to the marines and help stop ‘pissing matches’ between the forces.
Why do we need the Air Force? Surely it could be absorbed by the Navy.
We have the Marines now because there is a mission for them. It’s not like we found them in the corner and tried to find something for them to do. If we cut them, someone else will have to do that mission, and they will need an increase in manpower to do that. So you aren’t saving anything.
The Marines while a distinct fighting force, are under the Department of the Navy.
The Marines are built to force their way into where they aren’t wanted, expand their footprint, and secure the area for a short duration until the Army comes with the heavy equipment. The Army and the Marine Corps have two different distinct missions. They are equipped and trained differently.
No offense, but if the Marines and the Army are put shoulder to shoulder, the Marines will look like studs. If someone was coming to save me, I’d want it to be the Marines.
They have. The Navy maintains a small force of infantry who specialize in amphibious landings and quick reactions.
Any guesses as to what this force is called?
Then why not just expand the Marines and have them replace the Army?
You are missing the point. To what purpose?
Why aren’t they all lumped into one collective force called the Marvy force?
Just for fun, the next time you meet a marine call him a sailor.
Wild assed guesses at reasons for maintaining separate services:
The rivalry between the services helps all of them maintain higher standards.
Multiple services means that one person (other than the Pres.) can’t command all of our armed forces. Who knows, one day the marines may have to retake the capital from the army or visa versa.
The guys who fall off the boat?
Yes, there is shared ability between the SEAL teams and the other SOC groups, but none of them are as large as the Marines. Yes, the Marines also contain their own special operations (MARSOC) outside of the normal, but establishing a forward area and securing that area so that the other forces can move in is what the Marines do. The amphibious landing stuff is archaic, although possible. They’re a smaller, stronger, meaner ground force that’s used to introduce American troops into battle.
That’s what they’ll tell you.
The Army and the Marine Corps, while they have significant mission overlap, are still fundamentally equipped, trained and funded for separate missions. The Army is heavier, somewhat slower and built to stay. The Marine Corps is quicker, lighter and faster. Designed to get in and get out. They don’t have the staying power that the Army has.
The point you are missing is that we need a certain capability. Say we need a military of 1,000 ground pounders. We can have 100 in the Marines and 900 in the Army. Or 1,000 in the Army, or some other combination. But we still need 1,000. So what are you gaining be having them in one unit? There isn’t much cost savings at all, and you’ll use the unique capabilities
That’s what anyone will tell you.
I’m not a Marine (I’m Navy) but they are the best by a fair amount.
The SEALS do not do what the Marines do. They are covert troops meant to get behind enemy lines and collect intelligence and/or disrupt enemy operations.
If you want to take a beach and keep it for the Army to follow then you want Marines. SEALS probably wouldn’t be anywhere near that place. The last thing you could call the Marines is a covert force. When they show up you’ll damn well know it.