Within hours President Obama was notified, and the alarm grew over the weekend, as the munitions were loaded onto vehicles near Syrian air bases. In briefings, administration officials were told that if Syria’s increasingly desperate president, Bashar al-Assad, ordered the weapons to be used, they could be airborne in less than two hours — too fast for the United States to act, in all likelihood…

“I think the Russians understood this is the one thing that could get us to intervene in the war,” one senior defense official said last week. “What Assad understood, and whether that understanding changes if he gets cornered in the next few months, that’s anyone’s guess.”…

The United States military has quietly sent a task force of more than 150 planners and other specialists to Jordan to help the armed forces there, among other things, prepare for the possibility that Syria will lose control of its chemical weapons…

As the fighting has escalated, American and other allied officials have said that government troops have moved some of the chemical stockpiles to safer locations, a consolidation that, if it continues, could actually help Western forces should they have to enter Syria to seize control of the munitions or destroy them.