Before revision: This system broke down after the fragmentation of China by the era of the Warlords in 1916 and the First World War, causing most Western powers (with the notable exception of Japan which attempted to expand direct control) to be unable to effectively enforce their privileges in Mainland China.
After revision: This system broke down after the fragmentation of China by the era of the Warlords in 1916 and the First World War, causing most Western powers (with the notable exception of Japan which attempted to expand direct control) to be unable to effectively enforce their privileges in mainland China.