Illegal aliens dont go in the US military ..Only Registered Aliens (REAL immigrants with an Alien Registration Card AKA Green Card) do...
Dont mix the apples and oranges...
Its against the law for illegal aliens to serve in the US military..
The U.S. Military is having a very difficult time filling quotas, for the War In Iraq, Afghanistan, Iran, etc..,so they keep leaning, more, and more, towards a mercenary Army. Thus the offer to the (illegal) immigrants.