Remember, if you beat them, they're barbarians. If they beat you, they're monsters.

Brits: Wanna do drugs?
China: Nah, I’m-
Brits: (Loads shotgun) ITS DRUGS TIME.

The British simply had the Mandate of Heaven, it was foolish to oppose them when the Heavens clearly wanted them to rule over all under heaven.

They also specifically wanted you to have these drugs, trust me.

For the bri ish umpire, tha's jus another chuesday innit.

Money. Money and power. Those who seek will destroy anything to get it, and however much they have will never be enough.

Always

And then they demanded everyone criminalize drugs like cannabis and opium so they could sell them western pharmaceuticals. And the east complied so happily that they now brag about how "drug free" they are.

There was also tea at stake.

China enjoyed a trade surplus with Europe, trading porcelain, silk, and tea in exchange for silver. Trade between China and Britain was heavily imbalanced in China's favor. As Britain's demands for tea, silk, and porcelain exceeded Chinese demands for British goods, British merchants started exporting opium in India. This shift reversed the balance of trade.

And tobacco came before opium.