The "drug" war is entirely caused by society being crummy and having incomplete social safety nets. Those things should ALSO be fixed, but take far longer than a moderately sized reply to even begin to discuss. Staying on topic for just 'the drug war' and related arrests.
It would be trivial to make all of the criminals in the drug war vanish nearly instantly: just make getting a drug fix legal, cheap, and easy. (General reference, compare the Prohibition of Alcohol to booze today vs other drugs.)
Yes, some drugs are really bad, but making them not-legally-obtainable just means some criminal's going to fill the gap.