Why did tensions develop between great britain and china in the mid-19th century?

British traders refused to stop breaking Chinese laws against selling opium

Explanation: In 1839, the Chinese emperor ban the trade of opium in an attempt to cut down the illegal opium trade which has caused alot of social and economic instability. The British didn't go against the Chinese banning the trade of opium but they were not happy by the approach or strategies used by the Chinese in dealing with this issue. Some British traders were confined and food supply to them were cut off in an attempted to persuade them to surrender their opium goods without compensation. This lead to the dispatch of British military to China by the British government.