“It does apply. The regular Army cannot be used, nor can the Reserves or the National Guard if called up under Federal authority.”
You are saying the regular army cannot be used inside the US? What if the Russians or Chicoms attack us? Are we supposed to defend the country against a legitimate military force with our “assault rifles”? I believe the military can be used to defend our land against an invasion, just not for policing unless under martial law.
Did you read the article I linked to?