What causes most of the violence associated with illegal drugs?

Addiction

Explanation:

Hi, when people are addicted to drugs they become addicted and are not able to think rationally. They keep thinking this way until they are sober.

Answer: Most of the violence associated with illegal drugs isn't so much the drug itself, it's the people who go into the buy and sell "business" when it comes to drugs. Gangsters or people who run these drug operations fight over territory or product and that's what causes the real violence.