This question is becoming more important every day.
Politicians use it to justify more money for prisons.
The Pentagon uses it to justify their interventions, especially against the struggling people of Colombia. There are victims and there are casualties. The problem for workers and other oppressed people is that the ones who are supposed to benefit from drug-free streets are the targets and the victims. Take the domestic drug war. The main target of the war on drugs in the United States has been drug users and small-time dealers.