For 4 or 5 decades the Mexican government has allowed the cartels to smuggle drugs relatively freely, because Screw the Yanquis. Now Mexico - gooberment and normal people - is having to lie in the bed they made.
The US may have to help eradicate the cartels, for the good of US citizens, but it should come at the cost of Mexico abandoning giving free rein to drug smugglers, people smugglers, and others trying to enter the US illegally.