The ''Juche'' ideology is the cornerstone of party works and government operations. It is viewed by the official North Korean line as an embodiment of Kim Il-sung's wisdom, an expression of his leadership, and an idea which provides "a complete answer to any question that arises in the struggle for national liberation". ''Juche'' was pronounced in December 1955 in a speech called ''On Eliminating Dogmatism and Formalism and Establishing Juche in Ideological Work'' in order to emphasize a Korea-centered revolution. Its core tenets are economic self-sufficiency, military self-reliance and an independent foreign policy. The roots of ''Juche'' were made up of a complex mixture of factors, including the cult of personality centered on Kim Il-sung, the conflict with pro-Soviet and pro-Chinese dissenters, and Korea's centuries-long struggle for independence. ''Juche'' was introduced into the constitution in 1972.