The military, read National Guard, can and will do security. They are being sworn in by the state of Louisiana to do just that because Louisiana sure the hell can't handle security.
They are allowing citizen soldiers to assist the police, but they will not let enlisted soldiers do security. Although there was talk today of sending in some of the 82nd.
My friend from Secret Service is being sent to NO. His wife is a little afraid that he is going to pick up some kind of disease while he is there.