You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Muammar_Gaddafi

Context:
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.

Question:
Along with the United States, what country did Gaddafi believe to be imperialist?

Soviet Union