How does America know that Bashar Assad is planning a chemical attack against his own people? The same way we knew last time, because ’twas America who done it. And it’s the same refrain the US has used everytime.
Saddam launched a chemical attack against his own people. We’re worried that Saddam will resort to a chemical attack against his own people. Though of course, no trace of chemical weapons was found. Surprising that, because America HAD SOLD HIM chemical weapons.
Same in Assad’s case. This time they’re already in our possession. We have our covert proxies use them on absolutely whoever (Assad’s own people) and blame it on Assad.