Hitler against Stalin

Europe in the XX century became the arena of the multi -way geopolitical game of two historical figures: Hitler and Stalin. Despite the seemingly opposite of beliefs, they cooperated closely with each other. Each of them created a totalitarian state in which the cult of personality was planted, all dissent was suppressed, terror flourished. But was it possible to avoid a collision of two dictators and the beginning of World War II if the European continent was already divided into the spheres of influence?
In his new book, describing the political and economic state of Germany, the author indicates that Hitler could not fulfill his aggressive plans without Soviet raw materials and food assistance. Why did Stalin help Hitler until June 1941? What political mistakes of the Secretary General led to war?
The author collected the most striking and interesting materials about the time of the confrontation of two dictatorships