April Theses
During this time he developed the concept of using a foreign war to provoke an internal revolt within a country. It was at this time that Parvus revived, from Karl Marx, the concept-strategy of "permanent revolution". He communicated this philosophy to Trotsky who then further expanded and developed it. There were broad discussions on the questions of "permanent revolution" within the social democratic movement in the period leading up to 1917. The method was eventually adopted by Vladimir Lenin and the Bolsheviks in Lenin's April Theses in 1917.