My
 name is Daniel. I was an English teacher in Seoul, South Korea, and am 
now a writer and scholar who has written a couple of books including South Korea: Our Story by Daniel Nardini.
 
                        North Korean historians claim that Kim Il-sung 
led a powerful and massive guerrilla army against the Japanese, and had 
secret guerrilla camps established in northern Korea where he staged a 
revolt against Japanese rule. Kim eventually defeated the Japanese, but 
then the Americans came in and occupied the southern part of the 
country. Never happened. Before I say anything about what did 
happen, I should point out some important reasons why Kim Il-sung could 
not have done what is claimed he accomplished. First, how the Korean 
Communists could have maintained secret military bases in 
Japanese-occupied Korea without the Japanese knowing is pure fantasy. 
The Japanese decades before had defeated all of the Righteous Army 
guerrilla groups by 1907, and hence the Japanese were familiar with not 
only the land that the Righteous Army had fought from, but the Japanese 
created a vast network of spies, police informants and political files 
to keep track of the entire Korean population. Second, with this in 
mind, how could Kim Il-sung establish guerrilla bases in Korea at all? 
In order to exist, they would have needed housing, medical care, a 
steady food supply, a means of recruitment, and finally be able to 
obtain weapons. How could the Korean Communist guerrillas do all of this
 without the Japanese knowing about it? The Japanese secret police, the 
kempeitai, had spies everywhere and they most certainly could have 
tracked where there was any guerrilla activity. One other important 
detail to keep in mind is that from 1919 to 1945, there were no major 
revolts in Korea (there was the Gwangju Student Revolt in 1929, but even
 this had little impact on the rest of Korea). So Kim Il-sung leading an
 army into Korea to liberate it from the Japanese is a total myth.