The Western Faustian "European-American" civilization has "become", because it started around X century and by the many signs we are witnessing its winter phase already. The western civilization will end, because history is deterministic and unavoidable.
Thus there are actually three periods which tend to correspond to the 8 Cultures that Spengler defined. As a historian he suggested his concept for World history and defined 8 main "cultures" that naturally live around 1000 years, "Civilization" is the last, "winter" phase of every culture, when it is not becoming anymore, but "became". 1. Peasantry: The world of peasantry which is pre-Cultural and lived in the countryside. It is also outside “high” culture. 2. Culture: The period of Culture which grows and develops in the town and city. 3. Civilization: Each Culture begins to stagnate and die within the mega-city (mega-polis) which is a phenomenon of Civilization.
Spengler, Oswald, and Charles Francis Atkinson. 1926. The decline of the West. New York: A. A. Knopf.