the negative impact of the illegal drug trade on the supply side

If the demand side didn't exist, then the supply side would disappear. As such, I believe that countries with the most demand bear partial responsibility for the problems caused on the supply side.

where demand comes from

Here's national comparisons about where the demand for illegal drugs is coming from:

• drug consumption (per capita)
  • opiates
  • marijuana
  • cocaine
  • ecstasy
• TODO: is there any non-per-capita drug consumption statistics?
• drug use disorders

impacts on the supply side

In Colombia:

• five presidential candidates have been killed — Luis Carlos Galán Sarmiento, Jaime Pardo Leal, Bernardo Jaramillo Ossa, Alvaro Gómez Hurtado, and Carlos Pizarro Leongómez. (many of these were part of the UP / Patriotic Union party, which has been an intense target of violence).
• the Palace of Justice siege that left 11 of the 25 Supreme Court Justices dead
• (to give a sense of the scale) narco subs are being built in Colombian jungles at an increasing rate

In Peru:

• ...