Original sentence: Contrary to the commonly held erroneous  belief that the relations between the two neighbors only improved in the early 1990s after the collapse of the Soviet Union.The PRC launched the offensive largely in response to Vietnam's invasion and subsequent occupation of Cambodia, a war which ended the genocidal reign of PRC-backed Pol Pot's Khmer Rouge.The Sino–Vietnamese War or Third Indochina War was a brief but bloody border war fought in 1979  between the People's Republic of China (PRC) and the Socialist Republic of Vietnam
Edited sentence: China launched the offensive largely in response to Vietnam's invasion and subsequent occupation of Cambodia, a war which ended the genocidal reign of PRC-backed Pol Pot's Khmer Rouge.Contrary to the commonly held erroneous belief that the relations between the two neighbors only improved in the early 1990s after the collapse of the Soviet Union.The Sino–Vietnamese War or Third Indochina War was a brief border war fought in 1979  between the China and Vietnam