The most tantalizing problems faced by students of international relations are those which revolve around the question of motivation in national action. The rôle of ideas and attitudes in determining the behavior of nations is an obtrusive factor in every international situation. Among characteristic ideologies appearing as a growing determinant of national action is the German ideology regarding Lebensraum. Here is one of those words which have been in the German language for a very long time, but which has been popularized by the National Socialists. Literally translated, Lebensraum means “living space,” and when interpreted by anyone in Germany it is taken to indicate all that which is necessary for guaranteeing the life and development of the German people—physically, politically, and economically. It embraces all kinds of issues based upon prestige, historical, and geographical considerations. The terms “equal status” and “self-determination,” indefinite though they were, may have seemed to have definite limits; but Lebensraum goes much beyond them. It is the greatest single underlying cause of the war and the keyword of the new empire for which Hitler and his followers are struggling. The Nazis became increasingly convinced that nothing can save Germany except a genuine expansion of her Lebensraum and the unconditional return of her old colonies. This new empire must be consolidated in one compact mass in the center of Europe. First, the people of the same blood—Austrians, Sudeten-Germans—had to be incorporated; then the territory of Bohemia-Moravia, because of its geographical and strategic position, even though its inhabitants were mainly Slavs; while Slovakia had to be granted “independence” on account of “internal” disintegration.