How did the geographical size of the roman empire contribute to its decline and fall

Question

The fall of the roman empire.

Answer 1

A short answer is that the empire became so vast and the borders became so long that it was impossible to defend the empire from attacks coming from many directions.  For example, there were the tribes from northern Britain raiding southern Britain, the Germanic tribes attacking from Central Europe, a re-emergent Persia attacking from the Near East, and others.  In addition, as the empire grew and more nations and tribes were absorbed into it, the diverse peoples no longer identified with Rome, and they could not be counted on to loyally defend the borders.  Rome absorbed into its army peoples and tribes of dubious loyalty.