http://news.bbc.co.uk/2/hi/asia-pacific/country_profiles/1131421.stm
After the Korean War, Kim Il-sung introduced the personal philosophy of Juche, or self-reliance, which became a guiding light for North Korea's development.
"After the Korean War, Kim Il-sung introduced the personal philosophy of Juche, or self-reliance, which became a guiding light for North Korea's development"
I'm well aware of Juche, but that is not what lead to the downfall of North Korea's economy. What did destroy it was:
1. Stalinism, which destroys agriculture via collectivization, and instills a primitive concept of industry and technology.
2. Total lack of any entrepeneurial class--it all fled south.
3. A brutal and thouroughly corrupt regime which discouraged any sane person from investing in it.
4. The Korean War didn't help matters any; but the ROK was able to recover from the devastation economically because it lacked the first three handicaps (and had the US as a sugar daddy of sorts)