A file of reports, correspondence, and memoranda discussing the likelihood of the Soviet Union taking armed action against Yugoslavia following the falling out between Josef Stalin and Marshal Tito. Subjects discussed in this file include Yugoslav defence plans, including the possibility of their retreating to the mountains to carry out a partisan war; the causes of the Soviet-Yugoslav split; a comparison of the strengths of the armed forces in the Balkans; a report that Soviet forces in the region were too weak to mount an invasion; alternative outcomes of the crisis; and the Soviet desire to avoid provoking a major war with the Western Bloc.