In June 1973, Gaddafi created a political ideology as a basis for the Popular Revolution. Third International Theory considered the U.S. and the Soviet Union as imperialist, thus rejected Western capitalism as well as Eastern bloc communism's atheism. In this respect it was similar to the Three Worlds Theory developed by China's political leader Mao Zedong. As part of this theory, Gaddafi praised nationalism as a progressive force and advocated the creation of a pan-Arab state which would lead the Islamic and Third Worlds against imperialism.

In what month and year did Gaddafi begin Third International Theory?