what the obama administration or u.s. military would do, but potentially this is a huge development. >> well, wolf, let's get to some of the reporting that i've been doing on this issue. again, mentioning that the white house letter quite clearly calls it a small scale attack and still says they need to find more conclusive proof. but to some of the questions you've just been raising with some other reporters, as for what physiological evidence they were talking about. barbara starr was talking about that. i can tell you what the leader of the syrian opposition forces told me in an exclusive interview yesterday. they believe they've been told by their own forces inside that chemical weapons were used on at least three occasions, march 19th and that also corroborates what the israeli brigadier says. they claim have been used in homs, aleppo on two different instances and a suburb very close to damascus. when i asked him what physical proof, i asked this of the