Some left-wing historians of the 1960s and 1970s (most notably Eric Hobsbawn in his work "") claimed that the Paraguayan War broke out as a result of British influence on the continent, claming that as Britain needed a new source of cotton during the American Civil War (as the blockaded American South had been their main cotton supplier before the war). Right wing and even far-right wing historians, especially from Argentina, have also claimed that British influence was a major reason for the outbreak of war and Paraguay,