TOP SECRET ANNEX POSSIBLE COURSES OF ACTION BY THE SOVIET UNION TO REGAIN COMPLETE CONTROL OVER YUGOSLAVIA 1. We have already appreciated that politically, with the intensification since midsummer 1949 of the dispute between the Soviet Union and Yugoslavia, the stage is set for Russian aggression, motives have been manufactured, and all the normal political preliminaries completed short of a declaration of war. So long, however, as there is any possibility of overthrowing Tito by other means, Russia will not indulge in open aggression against Yugoslavia.