Does "closed their eys" in the following sentence mean "died"? A century ago, imperial China was said to be hoe to 100 million drug users, languid addicts who filled opium dens and closed their eyes as their proud country ebbed into chaos and war.
It is more likely to be interpreted as ignorning the troubles in China at that time - opium is a narcotic and will cause users to fall asleep/pass out so it may be simply that as well,
As is normally the case, Rekstout is correct. It is referring to a situation in which vast numbers of the chinese workforce were addicted to opium and economic chaos (which was already pretty bad due to the Dowager Empress being a drooling looper) getting a lot worse. Its another era of british bad behaviour: the opium wars and the various punitive expeditions were british methods of subjugating china and providing india with cash crops.