what we have learned from a senior us o.s.the communication intercepts of the syrian military and chemical experts talking about preparations for the sarin attack. what officials are emphasizing is, the u.s. had no knowledge ahead of time. but they scooped up a lot of intercepts. once the attack happened, they started going through all the intelligence they had and were able to isolate knowing the time, date and place of where the attack happened, then were able to isolate the intercepts they had on hand, look at them and get the evidence that, yes, the syrians had been communicating amongst themselves about planning for the attack. really, defense secretary james mattis hinted at that yesterday when he talked about so-called iron clad evidence, if you will, that the syrians had planned and executed the attack. the big unknown still remains, will they come up with similar intercepts or information indicating that the russians were involved? they don't have intercepts on that at this point. one of the things they are looking ve