Complex sentence: Such subjugation often elicited "client-state" resentment that the empire unwisely ignored, leading to the collapse of the European colonial imperial system in the late-19th century and the early-and mid- 20th century.
Split into simpler sentences: Such subjugation often elicited "client-state" resentment that the empire unwisely ignored. This would lead to the collapse of the European colonial imperial system in the late-19th century and the early-and mid- 20th century.