Indeed, and as usual the truth on HN is at the bottom.
The average age of a Khmer Rouge soldier was 17 years old and they were radicalized by what had happened to their villages during the American bombing campaign under the Lon Nol government, and then they were supplied with weapons by the Chinese. At least 100,000 Cambodians died from American bombings with many estimates being even higher. Many Cambodians starved during this period.
Add to that the level of regional instability with what had happened in Vietnam and Laos, and it's easy to see how some sort of catastrophe was very likely. Before this Cambodia was relatively developed and stable, and Phnom Penh especially was a phenomenal city, but the conflict incited huge tensions between the established powers and those residing in relatively poor areas near the border and in the center of the country.
No, moron, the drug war makes it much more dangerous to be a drug user. Ever heard of fentanyl contamination? Do you think that would happen if these drugs were produced and distributed legally?