As Meltyukhov asserts with his study, the General Staff of the Red Army had already begun developing a plan for an assault on Germany in October 1939. This process intensified in March 1940, and at least four different versions of the plan were developed throughout 1940 and 1941. The concentration of troops was disguised as maneuvers; in May/June 1941 the preparation for a Soviet invasion of Germany reached the final stage, as the full-scale concentration of troops began.[8]