The Opium Wars

It was a major drug bust with more than 1,600 arrests and the confiscation of 11,000 pounds of a highly addictive substance. No, this wasn't a DEA raid of a major meth operation, or an Interpol investigation into international drug smuggling.
It was the year 1839 and the Chinese government was cracking down on British importation of opium. The drug issue was a powder keg that led to a series of wars between the two countries over the course of more than 20 years and changed both nations for generations.