I've read that it was caused by a very complicated mix of things, one of which was resentment of the northern Manchu ethnic group which ruled China, combined with terrible floods and famine. Perhaps that's a case where lack of dignity helped cause war. People were starving, but in addition they felt disgruntled. I have a 1000 page book on that which I've been meaning to read for a year, so I'm sure I'll look back on this analysis and cringe when I finally get around to it.