I know: The Army is not the Marine Corps, the Marine Corps is not the Army. But what does the Corps do that the Army doesn’t, and vice versa? In terms of training and function.
Also, we have an Air Force for a reason, but there are Army pilots, Navy pilots and Marine pilots. So what does the Air Force do that isn’t covered by the air force of the other three branches?
(Also also, is it true that the other three branches look down on the USAF, and if so, to what extent?)
One more: The Coast Guard…guards the coast, but what is the limit of their authority?
The Air Force is the only branch which uses the A-10, which is the primary close-air-support plane used in combat. The Navy and Marines have fighter planes which can fly much faster and break the sound barrier, but the A-10 is critical for delivering bombings against enemy targets.
Traditionally, English-speaking countries have been nervous about combining military and police functions. So we have the Coast Guard to do law enforcement, and the Navy to attack foreigners. This is also why we usually deploy state National Guard units for natural disasters, while the federal Army is usually reserved for attacking foreigners.
The Air Force has more firepower, but it operates from relatively static bases. The Navy’s aircraft carriers enable it to strike some oddball place that suddenly became a threat overnight.
The Marine Corps is primarily a front-line combat unit. It is “first to fight” and “the point of the spear”. But if you want to hold ground, and govern conquered territory, you need the administrative bureaucracy of the Army or the Navy.
Army: Intended to fight and win vs. the nation’s enemies on the ground. What organic air support they have is legally limited to helicopters. The Army is the branch you call in to fight the bulk of an adversary’s ground forces.
Navy: Intended to fight and win vs. the nation’s enemies in the oceans/seas. As part of that, they have integral air capability on aircraft carriers.
Air Force: Intended to fight and win vs. the nation’s enemies in the air and in space. In general, they’re tasked with air/space warfare. They do air logistics, tactical air strikes, and strategic strikes.
Marine Corps: Originally organized as marine infantry, i.e. the guys who shot from the fighting tops and did boarding actions / landing parties in Age of Sail days. This evolved around WWII into them having a role as specialized amphibious assault forces. Since then, they’ve further evolved into a sort of somewhat heavier than paratrooper, but slower deploying rapid-deployment force, while retaining the same amphibious capability and developing helicopter-centric tactics as well. The USMC is relatively small- 3 active and 1 reserve division. AFAIK, the USMC has air assets because they like to deploy as a self-contained unit with integral air support.
Coast Guard: Not part of the Department of Defense like the other four armed forces(part of Homeland Security, and previously part of the Department of Commerce), it’s in essence the nation’s maritime police force. They do drug interdiction, search and rescue, etc… but don’t actually engage armed ships from other countries- that’s the Navy’s job.
I don’t think the Coast Guard was ever part of Commerce. It was part of the Department of Transportation from 1967 to 2003 and part of the Treasury before that. And technically part of the Navy during World War 2.
You’r describing them as if they’re supposed to fight three separate wars. In fact, the branches are designed to work together: the Navy and Air Force gets the Army where it needs to go and supports it when it’s there, while the Army does stuff like take and hold ports and airfields to support the Navy and Air Force. Their job isn’t to fight the enemy in different places - it’s to fight the enemy wherever the enemy is, with whatever means they have at their disposal.
The A-10 is being phased out by the Air Force and the Army & Marines don’t like it. The A-10 better known as the Warthog is not a primary bombing plane at all. It is an attack and especially a ground support jet.
The B-52s still are the major bomber in the in Air Force. The B-2 & B-1 are the more modern bombers B2 being the stealth bomber.
As to the Marines, it might be good to think of them as a large special forces unit. Perhaps the largest in the world. They concentrate on combat and leave a lot of the support to the Navy.
During times of war the Coast Guard is used against other country’s ships. In WW2 it was used against submarines, and for piloting landing craft during amphibious assaults.
In Vietnam Coast Guard ships were used to patrol rivers.
All the branches look down on the others. It’s a friendly rivalry.
As the saying goes, there are only two branches of the military the Army and the Navy. The Air Force is a corporation and the Marine Corps is a cult.
As for the Coast Guard, they don’t tell you which coast you are going to guard. My uncle was involved in 7 combat landings in the Pacific during WWII. In each of my deployments since 911 I have worked in some capacity with Coast Guard sailors overseas.
That is often misunderstood. There are two components of the active reserve force, the Army Reserve and the Army National Guard. The Reserves are primarily combat support and combat serviced support. You won’t find many front line troops in the Reserves. The National Guard is the Army’s primary pool of reserve combat troops. In the NG there are infantry, artillery, tanks and combat engineer units. Their function is to fight as combat troops in the nations wars.
The confusion comes from the duel role of the NG. The units also belong to the state and answer to the governor. The oath for the NG mentions the president and the governor. In times of crisis within the state the governor can activate them as state employees paid by the state. In times of war the Army activates them to fight.
In my 20+ years in the Guard after active duty I was always combat arms and only trained for my wartime combat mission. I never once trained on how to fight a hurricane.
The multiplicity of the branches serves the same purpose as the multiplicity of defense contractors. By ensuring redundancy and overage, some aspect of the military industrial complex can be found in every state and, I believe, in every House district. Congress is extremely reluctant, therefore, to ever cut a base, a function, or any part of the military’s budget. Instead, they compete for more.
The answer to the OP’s question is that there are no underlying differences. That includes the Coast Guard and its bases in West Virginia and Oklahoma. Or the Naval base in the mountains near riverless Saratoga Springs, NY.
Certainly not the first in the fight. That was the Army in the Philippines and the Navy in Pearl Harbor.
The Marines were the principle force during several well known operations in the Pacific but there were more soldiers than Marines in theater and the Army had more killed and wounded. The Marines have better PR and many think they conducted the war in the Pacific by themselves.
The Posse Comitatus Act prohibits the use of military personnel in law enforcement. This is why the Coast Guard is kept separate from the Defense Department. By placing them in Homeland Security, they are legally considered to be outside of the military so they can be used for law enforcement.
The Coast Guard also does drug interdiction in South America (with the cooperation of host countries), a fact I was surprised to learn just recently from Coastie boat driver.
Our current Air Force originated as the Army Air Corps, which was considered to be a branch of the Army (much like how the Marine Corps is considered to be a branch of the Navy).
The Air Force was split off as a separate organization in 1947. In 1948, there was a meeting between the members of the Joint Chiefs of Staff in which they decided what missions each branch of the armed forces would be responsible for. This meeting was held at Key West and the resulting policy is known as the Key West Agreement.
It was agreed that the Air Force would be the primary branch of the military for conducting air missions. The Navy and Marine Corps could maintain their own air assets in order to support their own missions (this basically meant that the Navy rather than the Air Force would operate the planes on aircraft carriers). The Army was supposed to mostly get out of air missions (it was only supposed to have air assets for reconnaissance and medical evacuation). The Army subsequently felt that the Air Force was failing to provide enough close air support to ground combat units. To get around this, the Army began developing an extensive force of helicopters which were not considered as air assets under the terms of the agreement.
It actually predated World War II. Back in the thirties, there were people asking why we needed to have a separate Marine Corps and why didn’t we have the Army and Navy cover all of the missions the Marines were doing. So the Marine Corps began looking around for a mission that nobody else was doing to justify its existence. They realized nobody else was training for amphibious combat so they began developing the ability to conduct those missions.
This turned out to be a great decision for the Marines. When Japan attacked the United States in 1941, we were at war in a situation where geography dictated amphibious warfare would be a major factor.
