The Second Opium War is a continuation of the First Opium War, mainly in terms of purpose and nature. The Second Opium War, like the First Opium War, was a war of aggression (in nature), aiming at opening the door of China and turning China into a raw material producing area and commodity market of capitalist countries. So the root cause of the outbreak is that Britain and France want to further open the door to China.
You didn't elaborate on the question of poetry. I hope you can be more specific.