[Lurking Libertarian]

Actually, Mexico has recently become the major Heroin source. So the writer has some facts wrong.

Maybe for heroin refining. But you can't make heroin without opium, and Mexico doesn't produce any opium poppies. So the ultimate source is still Afghanistan.

[Wuli]

You’re wrong. There is a sweet spot for growing opium in Mexico for growing the opium producing poppy and the drug cartels in Mexico have moved into it.

https://news.vice.com/article/mexican-heroin-the-destruction-starts-in-the-poppy-fields

[Harmless Teddy Bear]

Mexico doesn't produce any opium poppies.

Incorrect.

Mexico was producing opium poppies back in the 70's.

I doubt the weather has changed that much.