*During the Opium war alot of countries in Europe and America they were trading drugs with China. There economy was becoming weak because they werent paying any taxes becuase they was making alot of money. After a while China didnt want to trade with the European colonies and the United States because there economy was going down. China also decieded that they didnt want to trade any more with Great Britian. That was the cause of the war and the other nations were making alot of money off of them because alot of people wasgetting addicted to it. The opium war was called "The Opium war" becuase that was what they were trading ; Opium.