It is nothing in the coca or marijuana plant that causes death; it is all due to the prohibition and enforcement regimes associated with these plants that literally make them worth more than their weight in gold. As long as there are huge profits to be made, there will be people ready to kill over control of the massive, global illicit drug market.
Remember, when this country prohibited alcohol, we had gangsters like Al Capone and shoot outs similar to the ones happening today along the Mexican border. Now that alcohol is taxed and regulated, it has become laughable to think of people shooting each other over Budweiser.
The drug war leads to thousands of deaths and even more "collateral damage:" broken homes, shattered dreams. It is time for us to have an honest and open national debate about regulating illegal drugs so we can find an exit strategy from this other unwinnable war.