M.A.C.O. (Military Action / Combat Operations) - Starfleet, both pre- and post-founding of the Federation, refused to accept the mantle of a military organization. Unfortunately, the universe does not always bow to what you want, and Earth was forced to recognize the need for a military organization. The Military Assault Command Operations organization was created to protect fledgling humanity as it stumbled forth into space after Cochrane's warp flight made industrialization of space a practical venture. With the formation of the United Federation of Planets in the aftermath of the Xindi incident and the peace following the Earth-Romulan War, M.A.C.O. was disbanded with Starfleet Security expected to be capable of handling any issues that came up.
Always in the background was the question if this had been the right decision. Those questions got louder during the Federation's sometimes-cold/sometimes-hot conflict with the Klingon Empire; and really loud following the Setlic III Massacre, but ultimately quieted down as soon as peaceful life had returned. Then, the rising Borg threat came along; and soon after, intelligence began trickling in about the Dominion; and it was finally realized that the complete abolishment of M.A.C.O. had been short-sighted.
After fierce and intense debate, a new M.A.C.O. was formed as a division subbordinate to Starfleet, but also under the direct oversight of the Federation Council as a whole. Starfleet immediately returned Parris Island to military training and selected the West Point Military Museum as the Headquarters of the new organization as none of the other major military training centers (such as the Pentagon, Sandhurst, etc.) survived the nuclear holocaust of World War 3. Even Starfleet Command and Academy are both post-first contact constructions.
As soon as preparations were underway, Starfleet began contacting its allies for assistance. Andor, Tellar, and even some Klingons were brought in to help develop the training regimen for the new troops. Ranking and organization would be structured based on the historical designs of the United States Marines, and as soon as M.A.C.O. began recognizing the need for space-superiority fighter operations, they added fighter operations based on the US Air Force from pre-WW3. Training bases were rapidly established by reopening (Naval) Air Station Oceana as a pilot training field; utilizing the former Vandenberg Space Force Base as a major base as well as support staff training center; and opening Von Braun Station, a low-G training center near the Lunar North Pole; as well as a flight-combat training zone at the Jovian L4 point, and the establishment of the Bonaventure Proving Grounds near Proxima Centauri.
Even as they were only establishing the initial infrastructure, Starfleet already faced heavy upwinds to their efforts. Member worlds decried the establishment of so much military infrastructure in human-controlled space. Those privy to the classified data, feared that Starfleet was building up to turn the Federation into the Terran Empire. This fear became much more legitimate with Admiral Eric Leyton's attempted coup d'état against Federation President Jaresh-Inyo. Leyton's attempt very nearly derailed the re-establishment of the MACOs before it got underway; ironically potentially dooming the Federation and its Allies to defeat at the hands of the Dominion. Only when Starfleet brought Eric Leyton to court-martial, found him guilty of violating his oath to the Federation, and chose to hand him over to the Federation's Civilian Courts did much of the fever die down.
Starfleet justified these initial plans on the grounds that the Federation Council wanted direct oversight. Prior to his defeat in the general Election, President Jaresh-Inyo agreed with Starfleet Command's assessment the with Earth being the seat of Federation power: Office of the President in Paris; Starfleet Command in San Fransisco; (primary) Council Chambers in Geneva; it made sense to hold the MACO infrastructure close to where the governing oversight is. Also, once established and trusted, MACO had every intention of opening a basic induction center and training base within the sovereign territory of every member species that wished to have one. MACO intended to ensure its impartiality and loyalty to the Federation above any one member world, by making sure it bled in the colors of the member worlds that depended on its protection.
The new M.A.C.O. is primarily responsible for all ground-combat, non-away-mission ship-to-ship boarding actions, and all space-superiority fighter operations and the fighter support staff. M.A.C.O. also is responsible for its own logistics and supply-chain operations with its own "air-lift" capacity. In that regard, M.A.C.O. has a fleet of heavy-cargo carrying starships, but other than that, M.A.C.O. is prohibited from the operation of starships, being forced to depend on Starfleet, (a required restriction to appease Federation members worried about the militarization of the Union). Special dispensation was granted for the USS Churchill, which is a wholly-M.A.C.O.-crewed Defiant-II-class vessel, which is permanently assigned to escort duty with DSXG-1, the spaceQuest Carrier Group.
M.A.C.O. commands are normally structured from the basic unit up:
Three months after the First MACO Regiment deployed, the Alpha and Beta Quadrants were on notice, the MACOs were ready to fight, and they were here to win. The first fully-filled out Division of over 8,000 MACOs departed the Sol System. If Romulan Intelligence had really ever thought that the Federation had posed a true security risk to the Empire, it was nothing compared to having a true military force to reckon with.
Initially intended to be disbanded after the Dominion War, the reconstituted Federation MACOs look to have a long career ahead of them as continued unrest remains throughout the Alpha and Beta Quardants. This means the United Federation of Planets Member Council will need some means of answering the standing legions of battle-tested warriors of the Klingon, Romulan, Tzen'kethi, Tholian, and Breen empires. MACO stands ready for that need. MACOs know the limitations of their physical bodies, and have developed skills, technology, and techniques to overcome any deficiencies compared to the potential enemies they may face.
1MIEU (1st M.A.C.O. Interstellar Expeditionary Unit) - During the war with the Dominion, the M.A.C.O.'s were only just beginning to become an experienced fighting force. Though individuals had gone through the new MACO training, there really weren't enough at the onset of the war to make that much of a difference. Besides, most of the initial battles were starship/fleet versus starship/fleet. However by the time Captain Sisko had recaptured DS-9, the first combat regiment was ready to ship out... it was time to take the fight to the Jem'Hadar!
The problem with the Division is that it is so massive. It wasn't a tool Starfleet could realistically use without the infrastructure of War to back it up. They needed a smaller command to embark aboard starships. Two plans were drawn up, the first took a Regiment and added a traditional combat AirWing and a hybrid combat/logistics AirWing to create the standard Expeditionary Division. The other was a specially outfitted unit, specially crafted for forward deployment aboard large starships. This would become a fully self-sufficient forward MACO Command, prepared to defend any large starship or small fleet as needed. While being fully capable of handling any expected combat engagement, it was never expected for the IEU's to handle full-blown conflicts.
1MIEU is the first of these Commands:
The spaceQuest Class was designed with th eidea of an embarked MACO detachment from the beginning, including things like space for a command center, barraks, PE training, and even an entire deck outfitted with holo-emitters for use as a massive live-fire training center. At the rear of the ship, the four massive tailfins enclose a docking bay for the U.S.S. Churchill; the first, and presently only, starship crewed entirely by MACOs. This area can also be pressed into service as a full dry-dock for vessels up to the size of the (placeholder)-class U.S.S. Patton
946Wing (946th Space Superiority Fighter Wing) - During the Dominion War, it was recognized that while even minor starships could pool their firepower in fleets, massize numbers of single- and twin-seat fighters could out-maneuver enemy fire and grouped together, their weapons could be just as deadly as a massive starship, while being cheaper to build and crew. Named for the spaceQuest's registry, the 946th Fighter Wing comprises up to six fighter quadrons, two carrier-area patrol (CAP) squardons, one intelligence-gathering squadron, one dedicated med-evac squadron, and two logistical "air-lift" squadrons that can be redeployed if additional med-evacs are needed. Technically the 946th is a MACO command, however the Wing reports to the commanding officer of the spaceQuest once the carrier group breaks dock.
Starfleet has always had unique and distinctly recognizable uniforms, andmy story is no different in that regard.