Which theory was informed by social darwinism, and, also, formed the basis for environmental determinism; and, theorized that states were organism-like, needing "lebensraum" to grow?

The theory of organic state was created by Friedrich Ratzel, a German geographer in the early 20th century.

His theory stated that stronger states with greater culture are destined to grow by taking over the lebensraum, or living space of weaker states.

This theory based on extreme nationalistic and racistic ideas and misinterpretation of the work of Charles Darwin later became the foundation of Nazi ideology and the key element of the strategy for German territorial expansion in World War II.