Blood and soil was one of the foundations of the concept of Lebensraum, "living space". By expanding eastward and transforming those lands into breadbaskets, another blockade, such as that of World War I, would not cause massive food shortages, as that one had, a factor that aided the resonance of "Blood and soil" for the German population. Even Alfred Rosenberg, not hostile to the Slavs as such, regarded their removal from this land, where Germans had once lived, as necessary because of the unity of blood and soil. prescribed as the unvarying aim of foreign policy the necessity of obtaining land and soil for the German people (again, "German people" defined by the Nazi Party as racially pure).