What is the root cause of all the major emipres in world history having crumbled?

Answer 1

Immorality which is a greater threat to a country than terrorism.

Answer 2

Take a look at some empires, China for example. The biggest ethnic group in south China, Beijing could care less for. They are the Cantonese. Because Guangzhou is so far from Beijing, everything from the river to the field is mismanaged, too.
When you go out for Chinese food you are probably eating Cantonese food, because so many of them emigrated over the centuries, being neglected and left out of the party.
Same in the Roman Empire, the Judeans felt just as left out, and looked for a Messiah to free them from their colonizers, which only started a chain reaction when he actually came and did it.
America for the longest time has actually been in check, thanks to losing to Canada in the War of 1812, and nothing to the south except Mexico which we'd already picked clean and only left the pit. Thanks to geography we were sensibly put limits and our politicians considered us 'big enough', until we found another weaker area, like the middle east.

Answer 3

They become complacent and corrupt, or they are not stable enough to last long enough to survive.

For example the Roman Empire and The Ottoman Empire fell because of their decaying political structure and a series of incompetent, corrupt leaders.

Empires such as that of Alexander the Great, the Mongolian Empire, and the Empire of Qin Shi Huang, and Charlemagne's Empire all fell because no strong, stable leader was able to take power, causing them to fall apart.

Answer 4

It is almost always corruption and human imperfection that brings civilizations to their knees. Rome is a perfect example. It was once the greatest empire in history but was slowly grated away by greed and corruption.

Answer 5

My history prof said that all wars and conflicts throughout the beginning of time can be boiled down to one cause - money.

Answer 6

Imperialism. You create too many enemies taking over the world.

Answer 7

there are probably all kinds of complicated answers but I feel that societies forget what got them where they are. It takes a lot to reach a pinnicale but once there societies tend to take it for granted and if you are not moving forward you will eventually move backwards.

Answer 8

As soon as the population realizes it can vote itself free handouts from the government the downhill slide begins.

Answer 9

Because of their obsession to have all the power in the world. They basically want to conquer everything.

Answer 10

They got overtaken by other empires, à la Darwinian evolution but on a much faster timescale.