few more points

1. UNSC has access to tech from 500 years prior (A.K.A the U.S.)

2. We now the UNSC from games/books there is more to them than we know, We know everything that the U.S. Military has through daily news.

3.SPARTANS (explains it self)

4.UNSC-Giant flying space ships U.S.A.-Boat.

5.ODST's nothing can deploy that fast, and much better than the standard soilder.

6.The BR, if you read the Halo 2 hand book, it sais it fires Tiny explosives. 36 explosive rounds per clip.

7. on the humorus side in halo the UNSC dont have to reload and have infinite amounts of ammo.

8. how could the U.S. even compare?