Bro, rolled back to the American civil war with the British empire with American want independence. This war cost both huge amount money and wars are costly.
Both were dead broke and only way to build the 2 countries was a need for a criminal trade to quick make money and drug trade was targeted at China.
Nothing to do with cultures or anything but just both countries need massive amount of money to rebuilt their countries.
The French invasion of China says ALL the ultimate reason to weaken the Chinese to be ready for the final invasion of China.
But the Chinese were not easy push over.
Take Australia, Canada and America foe example, The natives were easy push over and now their lands were taken by the British bastards.
The Opium was named such because Opium was the instrument used for Britain to declare was on the Imperial Kingdom. The actual war was a clash of cultures between East and West, to open up trading ports that were closed to the West. Which led to opening up a closed-door China to the rest of the world. China is today what she is because all these happened. The foreign element in the Chinese Civil War resulted in the outcome of Communist versus Capitalists taking sides on both sides of the political divide within China leading up to Communist victory in 1949. Do not forget that U.S.A. and China were allies during WW2 fighting againsts a common enemy - Nippon. Who has since become the USA's friend. Do not blame China's ills on Opium or the foreigners. Opium was already used in Chinese medicine thousand year earlier, and used as a recreational class among the leisure classes in its society. the smuggers just made opium cheap and affordable even to the lowest classes - the Rickshaw Pullers! While it is true that many Westerners made enormous sums of money from opium in China, the local gangsters and corrupt police too lined tgeir pockets from the trade (including those resold after confiscation!) Everybody wants to grow rich. Too bad the government chose to outlaw it as contraband, they would have made a lot of money just be taxing its sale!
Cheers!