Why doesn't Mexico just legalize heroin and cocaine distribution? Wouldn't this put an end to the cartels?
The United States heavily punishes countries that legalize drugs, if not by direct sanctions, then by pulling aid. See how US threatened UN with pulling aid, and Pakistan.
Or for that matter, what crippling sanctions the US placed on Canada for legalizing pot?
The peaks days of the drug war are long over. The US has no real capacity to do anything to nations for such decisions, that has become very clear. As more nations and US states legalize and decriminalize, the pro war on drugs group will be and or is being shown to have very little actual power. At this point even the Republicans are increasingly coming around to the drug war being an absurdity. Jeff Sessions & Co. are dinosaurs on the way out rather rapidly, the US will probably have a majority of states legalized re pot within the next decade.