Haushofer defined geopolitik in 1935 as "the duty to safeguard the right to the soil, to the land in the widest sense, not only the land within the frontiers of the Reich but also the right to the more extensive "Volk" and cultural lands". Culture itself was seen as the most conducive element to dynamic special expansion. It provided a guide as to the best areas for expansion and could make expansion safe, but projected military or commercial power could not. Haushofer even held that urbanisation was a symptom of a nation's decline by giving evidence of a decreasing soil mastery, birth rate and effectiveness of centralized rule.