- assassination of dictator => internal turmoil
- early death of dictator => internal turmoil
- scuffle with neighboring country => economic sanctions by the free world
- dictator can't lose face, does something stupid => economic sanctions by the free world
- (Germany, Merkel, CDU) support for the dictator wanes and disappears => economic sanctions by the free world
- local governments cover up economic losses until its too great => hyperinflation, central government collapse
- triggering business defaults leading to dollar shortages leading to faster capital outflow => hyperinflation, central government collapse
- made up economic numbers are exposed => foreign businesses pull out
- nationalization of foreign companies assets => foreign businesses pull out
- natural disasters + lack of food supply => citizen riot
True, long term, China has sealed its future, but even if you half China's population, it will still be no. 1 in pretty much everything it is no. 1 today.
Pretty much nothing aside of war, civil war, or a second cultural revolution scale political crisis can stop it overtaking USA economically in coming 1-2 decades.