- last post: 01.01.0001 12:00 AM PDT
The majority of the Earth military is probably UNSC, ground troops on outlying planets were all UNSC, as were air troops, and everything else.
Once the Covenant attacked Earth (before that actually) propaganda was sent out to convince people to join the military (men and women) now that the choices have been limited to fight or die, whether you're in the military or not, I'm sure that almost everyone is in the military or military support staff.
No major cities means that Earthlings are now nomadic. The fastest moving best protected group is going to be the military, they're also going to be the ones with the best coordinated evacuation plan. I expect lots of Marines.
Also 5 Spartans versus 10,000,000 Brutes is not a fair fight... all 5 would have to tie their hands behind their back... or maybe be blindfolded.