" The British imperialist logic that led to the Opium Wars reflected this: there was a lot of silver in China, so the idea was to sell Indian opium to the Chinese, get all that silver out in that lucrative sale, and thereby pay for all the goods that were being produced in Manchester and sent to India. When the Chinese resisted opening their doors to the opium trade, the British response was to knock them down with military force. "

― David Harvey , A Companion to Marx's Capital