So did the US Presidents force China to not implement any environmental safeguards for their manufacturing? I don't think so.
Sure the corporations send the orders to China, and they pay for them, putting the money into China's economy. But China as a sovereign nation is still responsible for the pollution that it creates. They should implement strong environmental protection regulations to fix that.
I would prefer if American corporations sent their manufacturing orders to American factories, but I have no control over that or China's environmental regulations. They should both do better.