Pros & Cons of Drugs, and Stances of the War on Drugs#8

Is the war on drugs a good or a bad thing? Why does it exist?

Example Questions:

• Are drugs a tool of the rich to keep the layman weak and futile?
• Is the war on drugs a violation against liberty?
• Which drugs are better to be legalised, which are better to be illegal?
• Should they be illegal yet tolerated/regulated? Like prostituion and under-age drinking in certain countries?