the turks fighting the kurds and we often try to segregate those in boxes and say we're focused on isis and trying to deter chemical weapons, but not dealing with the broader conflict. elizabeth: the u.s. got more involved than in 2013, to target isis, but on the rebels, is that right? >> that's right, following the rise of isis which sort of stormed across syria and iraq unexpectedly and then started capturing the u.s. citizens, beheading some of them. the u.s. in 2014 started gearing up and then at the same time, had its own coalition, but was arming rebels on the ground, with the goal of both fighting isis and maybe also fighting the assad regime. elizabeth: so when did we see an up-tick in interest from russia. what vacuum did they fell and why is there such an interest. >> russia came in in 2015 and 2016 when it looked like assad was gaining ground for a--