You will unlock drug wars once you complete the second mission for Luis's mother. Armand and Henrique will be with you during them, they cant die but if they take too much damage they will vanish for medical help and wont return until the next mission.
Missions range from breaking up a deal, killing everyone, stealing money and stealing drugs to attacking a speed boat and stealing drugs. The missions end once you make it back to the hideout.
The following weapons can also be unlocked,
- 10 drug wars: Vice 9 pistol
- 20 drug wars: Advanced MG Rifle
- 30 drug wars: Explosive shotgun
- 40 drug wars: Sticky bombs
- 50 drug wars: Gold SMG