Western states expressed alarm after Syria acknowledged for the first time that it has chemical and biological weapons and said it could use them if foreign countries intervene.
I'd guess that's right. Use of chemical weapons on civilians or rebels would be an invitation to invade--hey, we'd have round two against a Baathist thug (with WMD confirmed rather than suspected)--but Assad has only that card to play to hold off the Turks.
Not that gas would stop a fast-moving mechanized force from advancing on Damascus. Troops can cope with gas if trained and equipped for it.
Of course, if Assad is really threatening Istanbul, that's another matter. Assad would count on civilian panic amongst Turks to scare off the invasion.
And if that doesn't work, Assad and his buddies would be shot and then tried for war crimes.
UPDATE: A more ominous take on Syria's threats. But I just don't buy that threats against Turkey or Israel for actions shy of overt conventional attacks on Assad's forces could lead to use of chemical weapons against Israel or Turkey. The former would reply with nukes on military targets--otherwise how does Israel maintain deterrence? The latter would bring in NATO air power. Heck, the former might lead to that to keep Israel from using a nuke in retaliation.
