well, really, we have a lot of reserves... there is a reserve for almost every section of the us military, even the marines have a form of it. the national guard are supposed to be used for national defense, border security, national disaster response.... but their role is rapidly being redefined.
i guess if a nation was to attack the us in a conventional manner with troops (something i cannot ever see happening in the current state of things, not because im an american, but..... it just isn't happening), i suppose you would see every branch of the us respond. the air force would bomb them, the navy would shell them, the army and national guard would be on the front lines, and the marines would be somewhere in that mess wrecking havoc.
but yeah, it would be nice to at least see some different uniforms on the americans....
karma back when i get some more....