The thesis of Weatherman theory, as expounded in its founding document, "You Don't Need a Weatherman to Know Which Way the Wind Blows", was that "the main struggle going on in the world today is between U.S. imperialism and the national liberation struggles against it", based on Lenin's theory of imperialism, first expounded in 1916 in "Imperialism, the Highest Stage of Capitalism". In Weatherman theory "oppressed peoples" are the creators of the wealth of empire, "and it is to them that it belongs." "The goal of revolutionary struggle must be the control and use of this wealth in the interest of the oppressed peoples of the world." "The goal is the destruction of U.S. imperialism and the achievement of a classless world: world communism"