Obama is justifying a military strike on Syria; Obama’s answer to “why are we getting involved?” during his “PBS Newshour interview” on August 28, 2013.
Starting around minute 12: "If we are saying in a clear and decisive but very limited way, we send a shot across the bow saying, 'Stop doing this,' this can have a positive impact on our national security over the long term."
Minute-by-minute live-stream updates by The Wall Street Journal live-stream website.