Any one who knows his/her tea, opium, coffee and chocolate knows a lot about the world. I don't know enough about cocaine to comment on it.
The battle for and between tea and opium is truly bizarre. Today we have war against drugs, the British were fighting for the opposite -- to make China hooked on opium (to counterbalance the import cost of tea) and then blame China -- you opium addled lesser civilization.
For anyone else reading, I'll mention that I found this book extremely engaging:
Rose, Sarah. For All the Tea in China: Espionage, Empire, and the Secret Formula for the World's Favourite Drink.