worked in the pentagon, i think our understanding of russian capabilities is very good. and it's also aligned with the fact that they've used advanced chemical weapons like noef n nov novichok. how do the syrian government's multiple uses of chemical weapons potentially factor into russian calculations with ukraine? >> i believe that russians calculating, because of the experience with syria, that he would be able to use chemical weapons or biological weapons in a perhaps targeted way. for example, on specific neighborhoods or population centers, the way assad did in syria. and potentially get away with it, in terms of not having a direct military response from the united states or nato. my understanding is that our national security adviser has