Military Assault Command Operations

Military Assault Command Operations (commonly abbreviated as MACO) was a United Earth military organization in service on Earth during the 2150s, prior to the founding of the Federation. The MACOs (pronounced "MAY-ko") were not associated with the Starfleet.

The military official that oversaw the MACOs was General Casey. MACO posts included Atlanta, Georgia and the Janus loop. Training posts included West Point in New York.

Equipment and uniform
Their weapon seems very similar to an MP5 submachine gun in function and size, including the three round burst mode. The stun grenades are also very similar to "flashbang" grenades. The rifle in sniper mode also bears a strong resemblance to the Federation sniper rifle from the Star Trek: Voyager - Elite Force video games, which preceded Enterprise.

Their Enterprise mission patch has a shark on it (almost certainly a reference to the species of shark.)

In the mirror universe, a skull appears on the patch. Both Malcolm Reed and Travis Mayweather are MACOs in the mirror universe. Their motto is "Ever Invincible."

MACOs after 2161
There have been no references to any separate Earth military after the final MACO appearance in 2161. There has only been one explicit mention of a Human holding an army rank after this point in history, and the officer in question – Colonel West – was shown to be a member of Starfleet in 2293 wearing a vice admiral's rank (which would make him a lieutenant general in the army).

It seems possible that Earth's entire military structure was absorbed into the UFP Starfleet. However, it is equally as possible that MACOs continued as a separate organization from the Starfleet navy, and that Col. West held a dual commission in both organizations. The process of dissolving, absorbing, or continuing separate service organizations as a sovereign world joins the Federation is unclear; however it is known that at least one other Earth organization, UESPA, had continued as a separate agency, albeit one that was seemingly part of, or at least working closely with, the UFP Starfleet. The last known UESPA reference, on the NCC-1701-B dedication plaque (also in 2293), means it is at least possible a pre-Federation agency could survive well over a century later.

It is also possible that West had the rank of vice admiral and the "billet" (military job) of colonel. (In the British army, a general in charge of a regiment can be called the .) As for the continued existence of the MACOs as part of the UFP Starfleet, the British Cavalry is part of the British Army, but it still uses its older traditional names for the ranks.


 * "Ground forces" were mentioned several times in latter season episodes of Star Trek: Deep Space Nine'', another possible passing reference to MACOs.

More info
links: http://memory-alpha.org/en/wiki/Military_Assault_Command_Operations