>> you can see it online. >> thanks for watching today. >> "state of the union with candy crowley" starts right now. make some great memories today. a picture is still worth a thousand words but will it sway a nation? today, u.s. intelligence agencies authenticate a series of horrific videos of what appear to be victims of sarin gas attacks in syria. a dvd designed to punctuate the president's argument that the u.s. must strike. >> we may not solve the whole problem but this particular problem using chemical weapons on children, this one we might have an impact on and that's worth acting on. >> in a pivotal week that includes top secret briefings and hearings and a political speech to the nation. the latest from chief of staff denis mcdonough and can a speech from someone as gifted as this