Hey, Navy ordnance:
To be honest, reponse time had never occurred to me when I was trying to understand where you were coming from in your posting.
My bad.
Even I have to admit, that the USA has it going on when it comes to being able to move troops around the globe.
Jeez, you folks have whole friggin' squadrons of heavy-lift aircraft, eg. C-17 Globemaster.
Canada's, just now, thinking about getting a couple, so we don't have to hitch rides on American flights.
Now, back to HaloWars....
Unless someone at Bungie decides to correct me...
I'm of the impression that the armed branches of the UNSC don't include an "Air Force", and for the simple reason that it's assets would most likely have been incorporated into the "Navy", to save on manpower and resources.
Why would you bother funding a branch that has been rendered obsolete?
For example, in today's militaries, there's no need to fund observation-type hot-air-balloons, like was used in WWI, as we now have UAV's et al.
If there was a need for planetary based "air"-craft, why not either use "Army" assets, Marine assets, or just have a Navy unit stationed there?
On the other hand, I don't see how there would not be a need for an "Army" even if were to just be considered as a kind of planetary "national" guard, plus, there is no way every nation would be willing to subordinate the entirity of their militaries to the UN.
Another reason for keeping an "Army" is simply for the ability to use them as a ready pool of personnel for reinforcing the Marines.
Then, keep in mind, there is, as has already been mentioned, the R & D element.
Who else, but the "Army" would be in the best position, geographically, to conduct serious research and development on anything dealing with surface combat?
Stuff like armoured vehicles, ballistics, artillery, superior vehicle armour, superior anti-armour weapons, body armour, and then there's always my personal favourites, grenades and other explosives.
Later.