> Yes, the US was funding the movements to overthrow Assad.
Meaning the US paid the fighters to move away from China.
The US doesn't control what those fighters do after that war is over (obviously, considering how often such fighters end up fighting the US itself); if they go back to China, that's not something the US is responsible for.
Now if you're actually alleging the US is paying Islamic fighters to go to China, that's a new claim and you should provide some evidence.
"helping Isis fighters relocate" and "throwing bags of cash" sounds pretty similar to me, if the cash leads them to China's border.