James Mattis, when testifying before Congress, stated "we're still looking for the actual evidence".
in other words, there was no evidence at all - obviously the videos from the white helmets were not considered to be credible enough .
on tv the other day, there was a clip about Mike Pompeo (must have been in relation to some senate/congress hearing for his nomination) - and he was asked about regime change (it must have been in relation to syria ) and his response was basically along the lines of "we are americans, we do as we please"
anyway, after the lies in relation to iraq and libya - who would trust these same people again