The Uniform Code of Military Justice is the set of laws applicable to all members of the military. Should the Naval Criminal Investigative Service report concerning Haditha support the need for an Article 32 hearing and should the Article 32 officer find that a recommendation for a court martial is warranted then he will make such a recommendation to the commander. It is the commander's responsibility to make a final determination as to whether to convene a court martial.
Just a very brief and incomplete primer as to the procedure that is underway regarding Haditha.
My bet is that if the Article 32 officer recommends against court martial we'll be hearing extraordinarily loud screams from the usual suspects concerning the need for Congressional hearings.