andrew tabler, is it clear or even close to being known who is behind it? >> it was behind the opposition's line, so it seemed to be delivered from the air, so that begs the question, well, who has air capabilities. the opposition does not. so it would be the assad regime or the russians. in that case i think most initial indicators are pointing at the assad regime. that then will, of course, focus attention on the assad regime's activities in the last few days. >> woodruff: as we just heard in margaret warner's report, international inspectors said a few years ago they determined assad regime had given up at least some of their chemical weapons. >> that's right. but at the end of the process, there was a concern about syria's declaration. so a couple things to look for in the coming days, if they find it was sarin that was used, which it seems from the symptoms that it was, that begs the question, where did it come from. if all of the stockpiles were destroyed, how did this sarin enter. if it's found to be chlorine, then it's another matter. but the syrian

andrew tabler is a senior fellow at the foreign policy think tank, the washington institute.the use of science, which they regine was supposed to not have had, —— the use of sarin gas, as a result ofa —— the use of sarin gas, as a result of a weapons deal in 2012, went well over a of a weapons deal in 2012, went well overa numberof lines. it of a weapons deal in 2012, went well overa number of lines. it was of a weapons deal in 2012, went well over a number of lines. it was not the first use of chemical agents, but it... i think it caused the drug administration to call the military strikes in syria. —— the trump administration. it sent a message to president assad, and i think it will be received. what is responsible, i am not sure. it was a unilateral response by the us. what have you made while watching the exchanges at the un of the international responses? there is some debate on this. the fact of the matter is, it is in noi's this. the fact of the matter is, it is in no 1's interest, including the 190 signatories of the chemical weapons convention, which syria agreed to

let's speak to andrew tabler who is asenior fellow at the foreign policy think tank, the washington instituterjoining us. —— much forjoining us. what choice do you think president trump had to do you think president trump had to do this? i think he had no choice. he use of sarin which the regime was supposed to not have had, as a result of the 2013 chemical weapons deal, which was over a number of, went well over a number of line, and wasn't the first use of chemical agents but i think it caused the trump administration to call strikes on syria, and make a very quick decision or send a message to president assad, it will be received now, what is response will be i am not sure. it was of course a unilateral response by the united states. what have you made while watching the exchanges at the un, of the international responses? well, there is some indication of this, but the fa ct of is some indication of this, but the fact of the matter is, that it is in no—one's interest, including the 190 i think signatories which syria agreed to if 2013, it is in all of their interests not to use, to use ch