"But none of the evidence has been made public, and many experts on
chemical weapons say that it is important to remain skeptical, that the
anecdotal evidence that has emerged is inconclusive and needs to be
investigated by an impartial organization. Some experts have been
mystified by the relatively low number of deaths, given the toxicity of a
nerve agent like sarin. They are also confused by the range of symptoms
seen in videos disseminated by Syrian opposition activists — including
some that seem mild — leading to questions about what kind of toxins
were used, but also the veracity of some of the videos. “There is probably something out there,” said Jean-Pascal Zanders, a
chemical weapons expert who has closely followed the events in Syria.
“But I don’t know what it is.”
Adding to the uncertainty, some experts said, is the incentive that
President Obama may have unintentionally provided to exaggerate the
reports. Last August the president said that the use of chemical weapons
by the Syrian government would cross a “red line” and “change my
calculus” on whether the United States should intervene in Syria — which
is exactly what many of Mr. Assad’s opponents have hoped for. “There’s a rush to draw conclusions that a red line has been crossed,”
said Joost Hiltermann, chief operating officer of the International
Crisis Group, who wrote a book analyzing the use of chemical weapons
during the Iran-Iraq war. An investigation into the current allegations,
he said, should rely on experts not aligned with states that have a
stake in the war, to rigorously establish the source of soil,
physiological or other samples. “We don’t know anything yet,” Mr. Hiltermann said. “Let’s be very careful.”"
