Bad neighbourhood

Drug abuse in Iran rising despite executions | GulfNews.com

This article says that drug addiction is a major, and increasing, problem in Iran:

Anti-narcotics and medical officials say more than 2.2 million of Iran’s
80 million citizens already are addicted to illegal drugs, including
1.3 million on registered treatment programmes. They say the numbers
keep rising annually, even though use of the death penalty against
convicted smugglers has increased, too, and now accounts for more than
nine of every 10 executions.

Living in a bad neighbourhood doesn't help:

Officials say Iran’s taste for illegal narcotics is certain to expand into greater abuse of heroin, simply because next door is Afghanistan, maker of three-fourths of the world
supply.

Abbas Deilamzadeh, whose Rebirth Society organisation runs dozens of rehabilitation centres, predicts that more people currently experimenting with meth soon will be
using heroin, simply because Iran is the main route for Afghan heroin dealers to export the drug worldwide.

The United Nations drug agency said the total area under opium poppy cultivation in neighbouring Afghanistan in 2014 was estimated at 224,000 hectares, a 17 per cent
increase from 2013, producing about 6,400 tonnes of opium. Most is grown
in the often-lawless Helmand and Kandahar provinces in the south.

Regardless of what people think about "the war on drugs", surely everyone can agree that the world  would be better off if Afghanistan, well, didn't exist.   (Nothing personal, all nice Afghanis out there.  It's just that your country has been exporting trouble for a very, very long time.)