"Syria would want to launch everything right away; they will have nothing to launch after the first few hours."
That would be a doomsday scenario for the Syrians. The use of chem/bio weapons against Israelis would mean Damascus would be no more.
I'm not sure the Russians gave this stuff to the Syrians during the transfer to Bekka...maybe they still control it or have neutralized the weapons in some deal with us to prevent its use against the American military....