Origins
Following the Korean War, the latitudinal division of the Korean peninsula between the Western-backed government in Seoul and the Stalinist revolutionaries in Pyongyang left Kim Il Sung and his political allies largely isolated. North Korea's decision to buck the United Nations agreement on unifying elections forced the Soviet-trained World War II veteran to look to his already grandiose cult of personality rather than Beijing or Moscow for political aid and cultural stability.
"Juche", meaning "self-reliance", was, at the most base level, the ideology used to qualify the absolute power of the North Korean dictatorship over opinion on the nation's political direction. It stated the absolute belief of the North Korean leadership that a socialist, and eventually communist, state would be achieved by the government without any outside aid - even from other Stalinist states. Article 3 of the North Korean constitution stipulates that the government "shall make the Juche Ideology of the Workers' Party the guiding principle for all its actions". The preamble to the party charter includes a pledge to Kim Il Sung and Juche as well.
The party and the state used Juche to oppose efforts of de-Stalinization forces from the South and to keep the people unified under the grave economic hardship that struck North Korea soon after its independence and the suspension of aid from the Soviet Union. When diplomatic relations opened on both Chinese and Russian fronts during the earliest disputes over those countries' borders, Pyongyang also cited Juche as the reason. The desire to create a uniquely North Korean doctrine of state-based socialism never truly existed: Juche was more a vacillating doctrine that could be used as a method of popular celebration and constant reiteration of the control that Kim Il Sung had over his people.
But like all true cults, it eventually became, as it once was, only about the leader.
Today
The Korean leadership began to emphasize the social, and even metaphysical, sanctity of itself through Juche's development in the politically turbulent 1980s. The Juche doctrine's isolationism had made North Korea desperately poor compared to its neighbor to the South, and Kim Sung Il knew well that dictatorial control had to be maintained at all costs. A new doctrine was expounded by the state that focused on the Leader (suryong) as the brain of a living organism made up of the masses; as the determinant of history and even of human progress; and on the faithful servants of the Leader as the only free-willed beings. The cult began to take on the trappings of a state religion, and public demonstrations of military power were conducted under its auspices. Any semblance of Marxist ideology faded into the secondary realm of scripture endorsing the current order. Of course, the constant economic aid on which North Korea began to subsist after later opening relations with South Korea undermined any true theoretical basis for Pyongyang's isolationism.
The doctrine itself continues in this form to the present day and is now all-pervasive under the succession of Kim Jong Il to the seat of power. Perusing more current Juche ideological documents (that is, those of the early 1980s), any reader will observe certain significant traits. There is little to no mention of any state or nation besides Korea, and that usually to a pristine, powerful and unified state at some point in the immediate future. Parallels to an eschaton are obvious: a unified Korea is less a diplomatic and domestic goal than an enforced article of faith. Similarly, the discussion of conditions in the country or any political topic solely exist in a dichotomy of evil-vs.-the Leader. The power and strength of the masses are declared as moving in concert with the mind of the suryong, with the result North Korea's wealth and prosperity; "imperialists" and "counterrevolutionaries" abound where people of definite nationality do not, replacing opposition forces with everpresent historical demons.
Most interesting is the way that even chronological history is structured within the documents. Resembling the Book of Revelation, statements on the North Korean condition are written like unchanging prophecy based loosely on the major talking points of Stalinism half a century ago. The history of the Leader is given in generic terms thick with glowing descriptive adjectives; his presence is marked, however, as though it were eternal in the terms of an Emperor or god-king.
Juche, at least according to its sources, has adherents outside of North Korea, including among the more authoritarian opposition in South Korea who find that what is too diplomatically friendly for the United States is far too obstructionist for them.
When dealing with North Korea, one is dealing with the cult of personality of Kim Il Sung, as represented on Earth by a perfect, identical successor in Kim Jong Il. Some modern diplomats seem to have forgotten that the paranoia fostered by a poverty-stricken population under an authoritarian religious state can be found outside of the realm of Islam - including in a country with a working ICBM program and nuclear capabilities (even if they are only being used for electrical power as North Korean authorities claim).
Lack of foreign engagement with such a leadership will lead to further incitement of its population through Juche. Opponents may face a cycle of paranoia that will resound in Pyongyang through the sort of hasty, unpleasant decisions for which North Korea is known - not the bending under pressure that is usually expected and received from such an economically ravaged state. Such states are usually tribalized, with ethnic and religious wars seething under the sparse military of a despot, as in Central Asia, the Middle East, and the Balkans. This state, however, has one people, one doctrine, and one church that may not hesitate to conduct a test of that doctrine on the international stage.
http://www.koreascope.org/english/sub/2/nk1_4.htm
http://www.cnet-ta.ne.jp/juche/defaulte.htm