The purpose of the address is twofold. First, he must blame someone else for what happened [even if he says he is ultimately responsible] and second, he must demonstrate to the people that he is not weak on national security, especially after his feckless initial response after the attempted bombing.
And you can bet he will defend his criminalization of terrorists [citing all the valuable actionable intelligence they received] and that he still is committed to closing Gitmo.
I’d love to hear O’Reilly’s body language expert’s description of 0bama saying “The buck stops with me.” It almost killed him.