Why did the British sell opium to the Chinese

The opium trade traffic grew in the western countries when Great Britain started growing opium in Indian land and sold it to China. They made huge profits by selling opium to China, and used the profits to buy chinese luxury goods like porcelain, tea and silk, which were greatly demanded in the western countries.

Tobacco smoking had already spreaded over the North America to China, and then the trade of opium also increased. Also, in the 18th century, the portuguese colonists found the usefulness of tobacco and thought of selling opium to China with huge profit margins. The Britishers also cultivated opium in large quantities in Bengal which enables the cheap production and selling of opium and in abundance.