As wars go, the Opium Wars were a truly dark chapter in British history. The Treaty of Nanjing, which concluded the war, also opened up China to foreign colonialism and intervention which left a lasting scar on the Chinese nation.
But they did have one positive, though somewhat ironic, benefit - had it not been for the Opium War, then Hong Kong (and Macau) would not have developed into the only examples of liberty, freedom and democracy within China. In a strange and unexpected way, a war between two of the oldest nations in the World led to the birth of a completely new society and national community in Hong Kong.