Pretty much nothing. Fentanyl for China is about an alliance with Mexico. China wants to be in USA's backyard. So this isn't a money thing for them. I expect the outcome of this is a shift to the precursor production in Mexico. There's not going to be a decrease in fentanyl for sure.

But since Mexico is already terrified of the US after Republicans said they wanted to invade, Mexico already let China's military come to work with them.

So all in all this is just a propaganda win for Biden. China's more than happy to just let Mexico make all the fentanyl themselves as long as Mexico continues to be friendly.