Re: In trade
whole opium for tea affair. That didn't go very well for them
To be fair, they did have a point - there was so much silver flowing out of the country (the Europeans wanted silver for their opium - by that point the British were already growing enough tea in the various bits of Empire that they didn't really need Chinese tea) that the Chinese currency was crashing (their currency was based on the silver tael and there wasn't enough silver left to make the standard coin so they had to debase the coinage..).
And the various European powers were forcing the Chinese government to allow people to buy the opium, despite the fact that it was illegal to do so in China.
So - not so much of a trade war as a "you will buy our poison that's killing your population" war.