The world socialist movement was in peril in the period of the late 1980s-early 1990s. At that time communist and workers' parties of some countries abandoned their faith in socialism as it collapsed in East European countries.

Under this situation, leader Kim Jong Il had conducted his energetic ideo-theoretical activities to arouse the world revolutionary parties to the struggle for defending and advancing the socialist cause.

He authored such celebrated works as "The Historical Lesson in Building Socialism and the General Line of Our Party", "On the Fundamentals of Revolutionary Party Building" and "Abuses of Socialism Are Intolerable" in the early 1990s to point out why socialism collapsed in some countries, review the historical lessons in building socialism and indicate the path of socialism.

His work "Socialism Is a Science", published on November 1, 1994, threw the world into a great excitement. The world progressives praised it as a "'Communist Manifesto' in the present times" and a beacon of hope, hardening their will to activate the socialist movement.

Thanks to his deep care and energetic efforts, the Pyongyang Declaration "Let Us Defend and Advance the Cause of Socialism" was adopted on April 20, 1992, with approval of the representatives of 70 political parties from the world. The Declaration elaborates on the principles, tasks and ways for defending and advancing the cause of socialism on the basis of the Juche theory on socialist ideology.

Since then, an increasing number of political parties throughout the world have signed the Pyongyang Declaration one after another in support of it.

In this regard, VOA said that the Pyongyang Declaration calling for the revival of socialism is a source of trouble more serious than the DPRK's ballistic missile and that it may bring a fatal calamity to the U.S. new world strategy sooner or later.

The revolutionary parties of the world still venerate Kim Jong Il as their honorary chairmen while regarding his works as their must documents and a guide for party construction and activity.