i want to go to j.m. burger in washington joining us. e's written books about him and is a partner at the brookings stus institution. thank you so much, j.m. we have some sound here on the square, i apologize for that. we'll try to keep you audible there. is it credible that al awlaki was behind this in the first place? >> it's definitely credible. according to what we've been hering as this event has unfolded and we've been getting more and more information, you know, the preponderance of evidence points to al qaeda in the arabian peninsula's involvement in this and one of the kouachi brothers having travelled to yemen and met with al awlaki. that does appear to be the case. >> you know the sound that i mentioned behind me is actually john lennon's "imagine" playing here on the square where so many gather against the kind of terrorism we're talking about here. i thought i'd note that in case it's audible for the audience. back to the calls for peace, why would the brothers have waited for three years after his death to execute on the att