The concern is that an order could come from President Bashar al-Assad to the military to use this against the Syrian people.
The military has loaded the precursor chemicals for sarin, a deadly nerve gas, into aerial bombs that could be dropped onto the Syrian people from dozens of fighter-bombers, the officials said…
U.S. officials stressed that as of now, the sarin bombs hadn’t been loaded onto planes and that Assad hadn’t issued a final order to use them. But if he does, one of the officials said, “there’s little the outside world can do to stop it.”
Secretary of State Hillary Rodham Clinton reiterated U.S. warnings to Assad not to use chemical weapons, saying he would be crossing “a red line” if he did so.