After about two decades as a foreign correspondent, I returned to the United States to find my country in a war I had barely heard of before. A lot of young people were dying by swallowing poison pills or injecting the poison into their veins. Americans took to calling it the war on drugs. Thousands had died by then, and before long thousands more would be killed because of organized gangs that were operating all over the world and harvesting billions of dollars. They still are killing, often gang against gang, but with far more powerful weapons than they had...