Greece was really rocky and supported growth of only a few crops,so they did trading to obtain food.
Rome was corrupted already by its large expanse. the it was the factor of the people. the peopl ewere not satisfied with what was going on like the persecutions. Another thing that was happing was the amoun tof terrible and unbenifactory leaders. Some such as Nero Destroyed parts of the empire. The last factor is Religion. When the Christians Came along, they pretty much indirectly destroyed Rome.
It belongs to the lithosphere