Cumings, Bruce (2011). The Korean War: A History. Modern Library. p. 35. ISBN 9780812978964. Various encyclopedias state that the countries involved in the three-year conflict suffered a total of more than 4 million casualties, of which at least 2 million were civilians—a higher percentage than in World War II or Vietnam.
Lewy, Guenter (1980). America in Vietnam. Oxford University Press. pp. 450–453. ISBN 9780199874231. The total number of Korean civilians who died in the fighting, which left almost every major city in North and South Korea in ruins, has been estimated at between 2 and 3 million. This adds up to almost 1 million military deaths and a possible 2.5 million civilians who were killed or died as a result of this extremely destructive conflict. ... we find that the ratio of civilian to military deaths [in Vietnam] is not substantially different from that of World War II and is well below that of the Korean War.